Elements of natural history, and of chemistry: being the second edition of the elementary lectures on those sciences, first published in 1782, and now greatly enlarged and improved, by the author, M. de Fourcroy ... Translated into English. With occasional notes, and an historical preface, by the translator.

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ELEMENTS

o F

NATURAL HISTORY,

AND OF

CHEMISTRY:

BEING THE SECOND EDITION OF

THE ELEMENTARY LECTURES ON
THOSE SCIENCES,

FIRST PUBLISHED IN 1782,

A N D N 0 W

GREATLY ENLARGED AND IMPROVED,

By the Author, M. DE FOURCROT,

DOCTOR OF THE FACULTY OF MEDICINE AT PARIS,
OF THE ROYAL ACADEMY OT SCIENCES, &C. &C. &C.

TRANSLATED INTO ENGLISH.

WITH OCCASIONAL NOTES, AND AN HISTORICAL
PR%£&CE, BY THE TRANSLATOR.-

'*

**n* or •»■■ \

VOL. IV.

a

LONDON:

//£

HINTED FOR G. G. J. AND J. ROBINSON,

pater-noster.ro w.

MDCCiXXXVIII.

C-Ta-uj-Vo^eL

CONTENTS

to VOL. IV.
PART III.

The Vegetable Kingdom.

CHAP. I. Concerning the Structure

of Vegetables. - - Page i

Chap. II. The Natural Philofophy of

Vegetables. j

Chap. III. Concerning Juices and Ex-
tracts. - - 1 6
Chap. IV. Effential Salts. - 23
Chap. V. Concerning the Saccharine

Matter. - - 31

Chap. VI. Concerning Gum and Mu-
cilage. - - 43
Chap. VII. Of Fat Oils. - - 47
Chap. VIII. Concerning EfTential Oils. 58
Chap. IX. Concerning the Campho-

rate Principle. - - - 61

Chap. X. Concerning the Spiritus Rec-
tor. 66
Chap. XI. Of Inflammable Refinous
Juices in general, and of Natural
Balfams in particular. - ~ 73
Chap. XII. Concerning Refins. - 76
Chap. XIII. Gum Reiins. - 82
Chap. XIV. Of the pure Fecula of

Vegetables. 92

Chap. XV. Concerning the Farina,

and Starch of Corn. 97

a 2 Chap.

( iv )

Chap. XVI. Concerning Vegetable Co-
louring Matters, and their Appli-
cation to the Art of Dying. - 106

Chap. XVII. Concerning the Analyfis
of Plants, by deftrudive Diftilla-
tion, or a naked Fire. - 114

Chap. XVIII. Of Vegetable Coal, or

Charcoal. - - - 122

Chap. XIX. Concerning the Fixed

Salts, and Earths of Vegetables 130

Chap. XX. Concerning Fermentation
in general, and the Spirituous Fer-
mentation in particular. - 136

Chap. XXI. Of Ardent Spirit, or the
Produd of the Spirituous Fernfen-
tation. - - - - 148

Chap. XXII. Concerning Tartar. 178

Chap. XXIII. Of the Acid Fermen-
tation, and of Vinegar. - 197

Chap. XXIV. Concerning the Putrid

Fermentation of Vegetables. - 217

p A R. T IV.

The Animal Kingdom.

Chap. I. The General Charaders of

Animals. - 222

Chap. II. Concerning Quadrupeds and

Cetaceous Animals. - - 226

Chap. III. Concerning Birds. - 234

Chap. IV. Concerning Oviparous Qua-
drupeds, and Serpents. - - 237

Chap. V, Of Fifties. - - 241

Chap,

( v )

Chap. VI. Concerning In feels. 246

Chap. VII. Of Worms. - - 255

Chap. VIII. The Functions of Ani-
mals, from Man to the Polypus. 258
Chap. IX. Concerning the Chemical
Analyfis of Animal Subflances in
general. - - 279

Chap. X. Concerning the Blood. 288

Chap. XI. Concerning Milk. - 300

Chap. XII. Concerning F>it. 316

Chap. XIII. Concerning the Bile and

Biliary Calculi. - 326

Chap. XIV. Concerning the Saliva,
the Pancreatic Juice, and theGaf-
tric Juice. - - - 333

Chap. XV. Concerning the Humours,
or Animal Matters, which have
not yet been examined ; fuch as
Sweat, the Nafal Mucus, the Ce-
rumen, Tears, the Gum of the
Eyes, the Seminal Fluid, and the
Excrements. - - 338

Chap. XVI. Concerning Urine. 342

Chap. XVII. Concerning Ammoniacal
Phofphat, the Phofphat of Soda,
and the Calculus in the Bladder. 353
Chap. XVIII. Of the Phofphorus of

Kunckel. - 369

Chap. XIX. Concerning the Phofpho-

ric Acid. - 383

Chap. XX. Concerning the Soft and
White Parts of Animals, and
their Mufcles. - - 391

Chap.

( vi )

Chap. XXI. Concerning the Bones of

Animals. - - Page 400

Chap. XXII. Concerning different
Subftances ufed in Medicine and
the Arts, which are obtained from
Quadrupeds, Cetaceous Animals,
Birds, and Fifties. - - 407

Chap. XXfIL Concerning the Pro-
duct of Oviparous Quadrupeds,
Serpents, Infedts, Worms, which
are ufed in Medicine and the Arts. 418

Chap. XXIV. Concerning the Putre-
faction of Animal Subftances, 433

Elements

T S

NATURAL HISTORY,

AND OF

CHEMISTRY,

dfc^cfrtifrtifrtifc<&tifctifrtifc&cfrc&<>&

PART IIL

The Vegetable Kingdom.

CHAP,

I.

Concerning the Structure of Vegetables.

EGETABLES are organized
bodies, fixed at the furface of the
earth, and pofleffing neither fen-
Ability nor fpontaneous motion.
They are diftinguifhed by their external ap-
pearance and conftrudtion, and differ more
particularly from minerals, in the circum-
Vol. IV» A ftance

2 STRUCTURE OF

ftance of their being nourished by introfuf-
ception, and their elaborating the juices de-
figned to increafe their bulk. They prefent
phenomena, which depend on their organi-
zation, and are called functions ; the prin-
cipal of which is, their reproduction, by
means of feed, or eggs, like animals.

Vegetables differ from each other, i. By
their magnitude : they are diftinguiihed into
trees, fhrubs, herbs, moffes, &c. 2. By
their places of growth : fome grow in dry,
and others in moift grounds ; others in fand,
clay, water, on the furface of ftones, or on
other vegetables, &c. 3. By their fmell, .
tafte, colour, &c. 4. By their duration :
plants are perennial, annual, biennial, &c.
5. By their ufe, either as food, medicine,
&c. A great number are ufed in the arts,
fuch as dying, &c. others' are ufed merely
for pleafure, ornament, &c.

Vegetables, externally confidered, are
formed of fix parts, or organs, deftined to
perform peculiar functions. Thefe parts
are the root, the ftem, the leaf, the flower,
the fruit, and the feed. Thefe differ in
form, texture, magnitude, number, colour,
duration, tafte, &c.

1. The root is concealed in the earth, in
water, or in the bark of other vegetables.
It is either tuberous, or fibrous, or bulbous.
Its direction is either perpendicular, or ho-
rizontal 3 and its confiftence, as well as its

form,

VEGETABLES* 3

form, is fubjecl to great variations. Bo-
tanifts diftinguifti them into feveral fpecies,
and avail themfelves of thefe diftin&ions, as
fpecific characters.

2. The Item grows out of the root, and
fuftains the other parts. It is either folid,
or hollow, ligneous or herbaceous, round,
fquare, triangular, or having two acute angles,
&c. The item comprehends the wood and
the bark. The wood is diftinguifhed into
wood, properly fo called, and fap. The bark
coniifts of the epidermis, the pulp or veficular
part, and the -cortical ftrata, or inner rind.
The ftem is divided into branches, which
have abfolutely the fame ftructure ; and the
diverfity of this part very often ferves to
eftabliih the diftincfive characters of the fpe-
cies and varieties.

3. The leaves of vegetables are exceed-
ingly varied. A By their form : they are
oval, round, fagitated, haftate, oblong, elip-
tic, cuneiform, &c. B By their polition
on their ftem : they are either feffile, pe-
tiolate, oppolite, alternate, ftellate, perfo-
liate, vaginant, &c. C By their margin :
they are either uniform, dentate, crenate,
ferrate, repand, undulated, lacerated, trun-
cated, &c. D By their fimplicity or com-
pofition : compound leaves are formed,
by the infertion of foliolas, or leffer leaves,
and are then either digitate or conjugate,
with either an odd or an even number of

A a leaves.

4 STRUCTURE OF

leaves. E By their pofition or place : they
are radical, cauline, or floral. F By their
colour, fmell, tafte, confidence, &c. Their
ufe appears to confift in abforbing the elaftic
fluids of the atmofphere, and exhaling dif-
ferent kinds of air, according to circum-
ftances.

4. The flowers are parts defigned to con-
tain the organs of generation, and defend
them till the fecundation is accomplifhed,
at which time they fall. The flower is dis-
tinguished into two parts : the external part
ferves to inclofe and protect the internal
part, whofe ufe confifts in reproducing the
plant. The former comprehends the calyx,
and the corolla. The calyx is external, and
green. Linnsus diftinguifhes it into feven.
fpecies -, namely, the perianthium ; the fpar-
tha, or (heath ; the hufk ; the involucrum ;
the amentum, or catkin ; the calyptra, or
veil ; and the volva. The corolla is the
coloured part commonly called the flower;
it is either monopetalous, or confifting of
one Angle piece; or polypetalous, confifting
of feveral parts. The fyftem of Tournefort
is founded on the corolla. The parts of the
corolla are called petals. The organs in-
cluded, and often concealed in plants, are
the ftamina, and the piftils or fiyles. The
ftamina are the male, or fecundating parts,
and are almoft always more nunv -ous than
the piftils. They confift of the filament,

and

VEGETABLES. 5

and the anthera. This laft, placed at the
extremity of the filament, is a fmall bag,
containing the fecundating powder. The
piftil is in the midft of the ftamina : it is
fometimes on another flower, or even on an-
other plant; which circumftance occalions
the diftin&ion of plants into male and fe-
male. The piftil confifts of three parts ; the
inferior part, which contains the embryo,
and is called, in Latin, germen ; the fila-
ment, which grows out of the inferior part,
and is called the flyle; and its extremity,
which is more or lefs dilated, is called ftigma.
The fexual fyftem of Linnasus is founded on
the number and pofition of the ftamina and
piftils. Mr. De Juffieu has eftablifhed a*
fyftem, founded on the infertion of the fta-
mina above or below the germen, &c.

5. Flowers are fucceeded by fruits. Bo-
tanifts diftinguilh {even fpecies ; the capfule,
the iiliqua, the legumen, the conceptacu-
lum, which becomes dry; fruits having ker-
nels, fruits having pippins and berries,
which remain fucculent. Thefe organs are
defigncd to inclofe the feeds, and defend
them from external agents.

6. The feed differs greatly in its form,
magnitude, appendices, 6cc. It contains
the plumula, or fmall plant ; the radicula,
and the cotyledons. Thefe laft are two in
number in moft vegetables ; but many fa-
milies of plants have no more than one co-

A 3 tyledon.

6 STRUCTURE OF

tyledon. This part is to the grain, what
the yellow and white of the egg is to the em-
bryo bird ; it contains a proper nouriihment
for the individual during the germination.

Vegetables, confidered with refpedt to
their internal parts, prefent five fpecies of
veflels, or organs, which exift in all their
parts; i, The common veflels, which con-
duit the fap : they are placed in the central
part of plants and trees, and rife perpendi-
cularly, though with lateral bendings, fo as
to form fmall vacancies between them. 2.
The proper veflels, which convey the juices
peculiar to each vegetable, fuch as the oils,
gums, reiins, &c. They are placed beneath
the bark, and appear in many places to be
dilated into cavities, or refervoirs, which
feem to be the excretory veflels. 3. The
tracheae, or veflels through which air circu-
lates : when a young green branch is torn
afunder, they may be obferved of a fpiral
form, refembling a cork-fcrew. They are
often filled with fap. 4. The utricles, or
fmall veflels, which contain a fecreted juice,
and frequently colouring matter. They are
placed in the middle of the ftem. 5. The
veficular tiflue, which exhibits a feries of
fmall cells, which leading horizontally from
the pith, and crofling the fap veffels, and fill-
ing the vacuities between them, are expanded
beneath the epidermis, form a kind of foft
covering, refembling the fkins of animals.

The

VEGETABLES, J

The veficular tilTue of vegetables appears
to anfwer to the cellular membrane of ani-
mals.

All the parts of vegetables confift of an
aflemblage of thefe five kinds of veffels, each
in particular being more or lefs numerous,
dilated, contracted, &c. The differences in
the form and texture of roots, items, leaves,
&c. depend on this diverfity of number and
difpofition.

Malpighi, Grew, and Duhamel, have been
the moft fuccefsful in their refearches into
the natural hiflory of plants, and their works
are the moft inftrudtive, with refped: to the
internal formation of their feveral parts.

CHAP. II.

The Natural Philofophy of Vegetables.

^*pHE organs of vegetables, which we
-* have concifely defcried in the forego-
ing chapter, are defigned to perform feveral
motions, which are called functions. Thefe
functions are,

i. The motion, or circulation of the

fluids,
2. The alterations, or change of thefe
fluids, by fecretion,

A 4 3. The

3 STRUCTURE OF

3. The augmentation and developement
of the vegetable by nutrition.

4. The exhalation of different fluids ela-
borated in the organs of vegetables, and
the inhaling of feveral principles con-
tained in the atmofphere, by the fame
organs.

5. The action of the air, and the ufe of
this fluid in the veffels of vegetables.

6. The motion performed by fome of their
parts.

7. The kind of fenfibility by which
they endeavour to obtain the contact of
fuch bodies as tend to promote the
functions, fuch as light, &c.

8. And laftly, The various phenomena
which ferve to reproduce the fpecies,
and conftitute the generation of plants.
We fhall confider each of thefe func-
tions feparately.

The principal fluid of vegetables, which
is known by the name of fap, is contained
in peculiar veffels, called the common veffels.
Thefe veffels, which are placed in the middle
of the ftem, and beneath the bark, are ex-
tended from the root to the leaves and flow-
ers. The fap which they conduct, is a co-
lourlefs fluid, of an infipid tafte, and, like the
blood in animals, becomes feparated into dif-
ferent juices, for the nourifhment and fup-
port of the feveral organs. It is very abun-
dant

VEGETABLES. 9

dant in the fpring, its prefence being then
fhewn by the production of leaves and
flowers. All the phenomena of vegetation,
as well as experiments made by applying li-
gatures about plants, mew, that it rifes
from the root to the Hem and branches.
But it is not fo well afcertained, that it de-
fcends again towards the root, as fome phi-
lofophers have affirmed. The valves ad-
mitted to exift, by many botanifts, in the
common veflels, have not been exhibited ;
unlefs we may call by this name certain
fibres, or hairs, with which their internal
parts appeared to be lined, according toTour-
nefort and Duhamel. Their regular mo-
tion of this fluid is very far from refembling
the circulation in animals.

The fap, when conveyed into the utricles,
and thence into the proper veflels, is elabo-
rated in a peculiar manner : it produces dif-
ferent faccharine, oily, mucilaginous fluids,
which are emitted in confequence of an or-
ganic procefs, and whofe evacuation feems
to be an advantage to the vegetable, fince it
does not receive any damage from a very
confiderable occafional lofs of thofe matters.
This alteration of the fluids, which is very
obfervable in many organs, as in the necta-
rium, at the extremity of the piftil, in the
pulp of fruits, at the bafe of the calyces, and
of many leaves, is produced intirely by that
function, which in animals is called fecre-

tion.

10 STRUCTURE OF

tion. Guettard has carried this analogy {q
far, as to defcribe glands of various forms
at the bafes of the leaves of fruit trees, and
towards the inner extremity of the petals of
certain flowers. It is this fecretion which de-
velopes the principle of fmell, the colouring
matter, the combuftible fubftance, &c. But it
differs very effentially from animal fecretion,
which is intirely produced by the organiza-
tion of the glands, which elaborate the ani-
mal fluids ; whereas, in vegetables, the
juices contained in the common veffels are
more expofed to the contact of air, light,
and the aftion of heat; and their fituation
renders them capable of paffing through the
proceffes of fermentation by means of thefe
agents.

The fap, while it remains in the cavities
of the utricles, and of the veficular tunic,
becomes thick, and more confident. This
alteration renders it capable of adhering to
the fides of the fibres, and of gradually aug-
menting their dimenfions. Such is the me-
chanifm of the nutrition of vegetables, their
increafe of magnitude, and the developement
of their parts. It greatly refembles the nu-
trition of animals. The veficular tunic, and
the utricles, have the fame conformation,
and the fame ufe in both claries of organized
beings. In both, they penetrate all their
organs, eftabliihing an immediate commu-
nication

VEGETABLES. II

nication between them, and in both they
are the true feat of nutrition.

Philofophical botanifts have long been
convinced, that exhalations are emitted into
the air from the furfaces of plants. The odo-
riferous exhalation of leaves and flowers forms
an atmofphere around vegetables, which
ftrikes our fenfes, and which the contact of
a body on fire is fometimes capable of in-
flaming, as has been obferved with regard
to the fraxinella. This exhalation appears
to be a peculiar kind of inflammable gas.
Experience has likewife fhewn, that many
vegetables emit vapours which are mortal
to fuch animals as remain long expofed to
them. Such are the yew, and many trees,
natives of hot countries. The experiments
of Mr. Ingenhoufz have fhewn, that the
leaves of all plants expofed to the light of
the fun emit an invilible fluid, which con-
fifis of true vital air, fimilar to that which
is obtained from calces of mercury, &c.
This property of leaves is intirely changed
in the (hade, in which fituation they e-
mit the cretaceous acid. This happy dif-
covery, firft publilhed by Dr. Prieftley,
fhews an unfufpedted property in plants,
namely, that of purifying and renewing the
air, by reftoring that portion of vivifying
fluid which is continually deftroyed by corn-
bullion, refpiration, &c. But at the fame
time that vegetables continually emit vapo-
rous

12 STRUCTURE OF

rous fluids produced in the laft proceffes of
vegetation, they likewife abforb many of
the principles contained in the atmofphere.
The lower furface of leaves abforbs the hu-
midity of the dew, according to the expe-
riments of Bonnet. Dr. Prieftley's experi-
ments likewife prove, that vegetables abforb
the gafes, which remain after combuftion
and refpiration, and that vegetation is
ftrongeF in air changed by thefe proceffes.
The exhalation and inhalation at the furface
of vegetables are confequently much more
confiderable than was fuppofed before the
time of the modern difcoveries. It even
appears that the water abforbed by the in-
ferior furface of leaves is decompoied ; that
the bafe of inflammable air it contains is
abforbed ; and that the pure air difengaged
from the fuperior furface of the leaves is
produced by the oxyginous principle con-
tained in that fluid. The contact of the
rays of the fun contributes greatly to this
decompofition, as it does not take place in
the fihade. Plants defended from the action
of light, abforb water intirely without de-
compofition, and become white, infipid, and
foft; a much lefs quantity of coloured, com-
buftible, or oily matter, being formed.

The gafes abforbed by vegetables, are con-
veyed into all their organs by the air veiTels,
which in their ufe and ftru&ure refemble
thofe of infe&s and worms. The air vef-

fels

VEGETABLES. I3

fels are not, however, appropriated folely to
the circulation of elaftic fluids ; for they are
obierved to be filled with fap, at thofe times
of the year in which that fluid is moft abun-
dant : a circumftance which conftitutes a
great difference between them and the organs
of refpiration, fo eftential to the exiftence
of a great number of animals. From the
theory of refpiration, which we have ex-
plained in the hiftory of air, it is eafy to
(hew why the temperature of vegetables does
not exceed that of the air which furrounds
them.

It cannot be doubted, but that many parts
of vegetables have an internal principle of
motion ; in forne it is fo evident, as to be
moft obvioufly diftinguifhed. Such is the
motion of the feniitive plant, of the (la-
mina of the Indian fig, of pellitory, &c.
This motion feems to depend on the func-
tion, which is known in animals by the
name of irritability ; for it is excited by the
action of a ftimulus, and has peculiar or-
gans, which fome botanifts have compared
to mufcular fibres.

Ought we not to admit a fort of fenfibi-
lity in plants, when we obferve them to
turn their leaves and flowers towards the
fun, and when we obferve that plants, in-
clofed in wooden boxes, glazed on one fide,
perforated, or merely thinner on one fide
than the others, conftantly tend towards the

tranf-

14 STRUCTURE OF

tranfparent body, or the aperture through
which the light pafles, or even towards the
fide, which by its lefs thicknefs may admit
a glimmering light ? Or may we not attri-
bute this apparent fenfibility to the force
of affinity, or tendency to combination,
which exifts between vegetables with light ?
It is well eftablifhed, that this fluid, either by
percuffion or combination, affifts in produc-
ing the colour, tafte, and combuftible property
in plants; becaufe plants, which grow in the
fhade, are white, infipid, aqueous, and con-
tain no inflammable matter -, whereas vege-
tables expofed, in the burning climates of
the fouth, to the ftrong rays of the fun, be-
come highly coloured, abound with bitter
and refinous parts, and are eminently com-
buftible. However ftrong we may fuppofe
this affinity to be, we cannot conceive how
it fhould be capable of exciting a motion fo
confiderable in the branches and leaves of
vegetables. We muft therefore neceftarily
admit a peculiar kind of fenfation, or feel-
ing, very different, it is true, from the fenfes
of animals, by means of which vegetables
give a preference to fuch fituations as are
mod acteffible to light.

The manner in which the fpecies are pro-
duced, among vegetables, greatly refembles
the generation of animals. The exiftence
and union of fcxQS are neceffary in the great-
eft number of plants. The labours of the

celebrated

VEGETABLES. 15

celebrated Linnaeus have difcovered a ftrong
analogy between the organs deftined for this
function in the two claffes of organic beings.
The ftamina correfpond with thofe of the
male fex, and the piftil is compofed of three
parts, analagous to thofe of the genitals of
female animals. The embryo is developed,
by the a&ion of the fecundating powder,
without which it is not capable of pro-
ducing an individual, as is likewife daily
obferved among birds. But befides this
analogy, which need not be further purfued,
vegetables are of a much Ampler ftrudture
than animals ; and all their parts being com-
pofed of the fame organs, each is capable of
producing a new individual fimilar to itfelf.
This is the reafon of the reproduction of
plants, by means of fcions or flips, as well
as the alteration of the fluids, by grafting,
whether natural or artificial. There is like-
wife another analogy, of modern difcovery,
between vegetables and that clafs of animals
which is reproduced, by diviflon into pieces,
as the polypus, cruftaceous infedts, certain
worms, &c.

All the functions, which, taken together,
conftitute the refemblance between vege-
tables and animals, are fufceptible of alte-
rations, which produce diforders. Thefe
depend, moft commonly, , on the abundance
or defed; of the fap, as well as its bad qua-
lities, and are analogous to thofe which take

. place

%

l6 JUICES AND EXTRACTS.

place in animals. Their caufes, fymptoms,
and cure, are alike referable to the general
principles of medicine, and form a part of
agriculture, which it muft be confeffed is
not much advanced, but capable of great
improvement, according to the plans of fe-
veral celebrated authors.

CHAP. I1L

Concerning Juices and Extracts.

'T^HE fluids contained in vegetables, are
■* of two kinds ; the common, and the
proper juices. The firft, confifts of the fap
which is found in all plants. It is contain-
ed in the common veffels, flows naturally
out of their furface, but is more abundantly
extracted by incifion. The fap is not merely
an aqueous fluid, but contains falts, ex-
tracts, and mucilages. When a certain quan-
tity is defired, either for medical ufe, or
philofophical inquiry, the plant is beat in a
mortar, and prefled in a cloth, beneath a
prefs, if neceflfary.

Succulent vegetables give out their juice
by fimple expreffion ; but thofe whole juices
are vifcous, or in fmall quantity, require to
be diluted with water, fucri as borage, and

the

PRINCIPLES OF VEGETABLES. 17

the dry aromatic plants. This fluid being ex-
tracted, by ftrong prefTure, is found to contain
a portion of the folids of the vegetables beaten
fmall by the peflle, and confequently re-
quires depuration ; which may be effected
either, A By fubiidence, or filtration, when
they are very fluid, as is the cafe with the
juice of purflain, houfeleek, &c. B By
white of egg, which collects the fecula, by
coagulation, as is requifite with the juice of
borage, nettle, &c. C By Ample heat,
which coagulates and precipitates the pa-
renchyma, as Mr. Baume advifes, with re-
fpedl to juices that contain volatile prin-
ciples, fuch as thofe of cochlearia, creffes,
&c. The phial which contains the juice,
being covered with a perforated paper, muft
be plunged in boiling water, and taken out
as foon as the juice is clarified. Immerfion
in cold water brings it to a proper tempera-
ture for filtration ; D By fpirit of wine,
which coagulates the fecula; E By vegetable
acids, as the London Pharmacopeia prefcribes
for the juices of cruciform plants.

The juices of plants hold in folution mat-
ters which, when feparated from the aque-
ous vehicle, form what, in pharmacy, are
called extracts . Thefe are diftinguifhed into
three kinds ; mucilaginous, faponaceous, and
gum-refinous extracts.

Mucilaginous extracts, are fuch as readily
diffolve in water, fcarcely at all in fpirits of

Vol, IVt B wine,

l8 PRINCIPLES OF VEGETABLES.

wine, and undergo fpirituous fermentation :
fuch is the rob of goofeberries. prepared
by evaporating the juice of that fruit.

Saponaceous extracts are diftinguifhed by
folubility in water, and partly in fpirit of
wine ; they become mouldy, inftead of pafT-
ing to the fpirituous fermentation. The
juice of borage, when converted into an ex-
tract, is of this nature; and thefe are ex-
tracts properly lb called.

Gum reiins diilblve in water, and in ar-
dent fpirit ; they are inflammable, by virtue
of the refinous principle they contain, and
are not changed by expofure to air. The
concentrated juice of wild cucumber, called
elaterium is of this kind. Incifions are
made in the fruit; and the expreffed juice
being fuffered to clarify, by repofe, is eva-
porated to drynefs on the water bath.

Extracts of thefe three different fpecies
are prepared, in the large way, by evaporat-
ing the juices of feveral plants. Such,
among others, are,

i. The juice of acacia, imported from
Egypt, where the fruit of this tree is mafh-
ed, preffed, and the juice expofed to evapo-
ration by the fun's heat. The infpiffated
juice of floes is prepared, in Germany, by a
fimilar procefs, and fold under the fame de-
nomination.

2. Thatofhypociftis, which is made like

the

PRINCIPLES OF VEGETABLES. 19

the foregoing, with the fruits of this para-
fitical plant.

3. Opium, an important medicine, whofe
nature is not accurately known. It is ex-
tracted from the white poppy, in Perlia, &c.
where it flows through incifions made in
the green capfules of the plant, in the form
of a white juice, which dries into brown
tears of the true opium. The opium of
commerce is obtained, by preffure, from thefe
capfules, moiftened with water, and comes
to us in a dry form, in flat circular cakes,
wrapped up in leaves, and mixed with many
impurities. It is purified by folution in as
fmall a quantity of water, as is fufficient to
fufpend it -, which being filtered, or ftrained
by ftrong preffure, is evaporated on the wa-
ter bath. This is the extradt of opium, and
contains a faponaceous extract, a folid effen-
tial oil, an odorous, noxious, and narcotic
principle, an efiential fait, and a glutinous
matter. As the odorant, poifonous and nar-
cotic principle, is often productive of bad
effects, attempts have been made to obtain
an extract of opium, deprived of this prin-
ciple. Mr. Baume, who has made many
experiments on opium, volatilized this prin-
ciple, together with the efiential oil, and by
that means feparated the refin, after a di-
geftion of fix months. Bucquet has difco-
vered, that the fame fedative extract, with-
out the narcotic property, may be obtained

B 2 by

20 PRINCIPLES OF VEGETABLES.

by diftblving opium in cold water, and eva-
porating the folution in a water bath. Lor-
ry, who has made fuccefsful inquiries into
this fubjedt, finds, that opium, after fer-
mentation, affords a diftilled water, which
has the fedative property, without produc-
ing the bad effefts of the crude fubftance,
and which he has ufed with great fuccefs.
He obferves, that the odorous principle of
this medicine cannot be deftroyed by any
procefs.

When the plants, from which it is pro-
pofed to make extracts, are dry and ligneous,
maceration, infufion, or decodlion in water,
are employed, according to the ftate and na-
ture of the materials : maceration is, in moft
cafes, fufficient. Odoriferous plants muft
be only infufed ; decoction extradls too
much, and feparates the refinous parts,
forming a thick fluid, which becomes tur-
bid on cooling. Infufion may be ufed, in
all cafes, according to the opinion of the
moft celebrated phyficians and chemifts.

Water extra&s various products from fe-
veral plants. Thus the berries of juniper
afford a mucilaginous extradl ; quinquina
affords a faponaceous extradl, in fmall trans-
parent fcales, refembling falts, if the eva-
poration be made in very mallow veffels ;
and rhubarb affords a gummy refinous fub-
ftance.

The faponaceous, or more properly the

chemical

PRINCIPLES OF VEGETABLES. 21

chemical extradt, appears to be a com-
pound of oil and fixed vegetable alkali. The
extracts, prepared in pharmacy, are very far
from being all of the fame nature -, they are
mixed with mucilage, effential fait, faccharine
juice, refin, &c. From thefe confiderations,
Rouelle, with the intention of illuftrating
this part of medical chemiftry, diftinguifhed
them into the three genera we have men-
tioned : but the pure extract, reckoned a^
mong the immediate principles of vegetables,
muft be confidered as a faponaceous com^
pound, pofTefiing peculiar properties,

Extra&s are prepared in the large way, in
commerce, by means of water. Such as,

i. The yellow juice of liquorice, by the
iirft infufion, or black, by ftrong deco&ion.
This laft is burned, and contains a true char-
coal. It is purified by folution in water,
filtration, and evaporation, ufually with the
addition of fome effential aromatic oil of
annifeed, cinnamon, &c.

2. The cachou, or, as it is improperly
called, Japan, earth, is prepared in the Eaft
Indies, from the infufion of the feeds of a
kind of palm, called areca, the infufion be-
ing evaporated, and made into cakes. It is
purified by folution in water, and evapora-
tion, ufually with the addition of aromatics.

Among the extracts prepared for medical

ufea Rouelle particularly diftinguiflied thofe

B 3 which

22 PRINCIPLES OF VEGETABLES.

which are mixed with refin, by the names
of gum refins, and refinous extracts.

Gum refins do not burn without being
firft dried, and appear to contain a larger
quantity of extract, properly fo called, than
of refin. The refinous extract burns much
better, and appears to contain more refin,
than extra&ive matter. This happy diftinc-
tion mews, that the two fpecies confift
fimply of mixtures of extract with different
dofes of the refinous principle. They are
not, therefore, with propriety called extracts,
that name being applicable only to the fapo-
naceous matter, whofe properties we mail
proceed to enumerate.

The pure extract differs from the forego-
ing : it is a dry, folid, brownifh red, tranf-
parent fubftance, which does not burn by
itfelf, but emits plentiful fumes, and con-
tains more or lefs efiential fait. Its tafte is
almoft always bitter; by diftillation, it af-
fords an infipid phlegm -, this phlegm, by a
mild heat, becomes gradually of a deeper
colour, and afiumes alkaline properties, as
is obfervable with elaterium, extract of bo-
rage, &c. The volatile alkali is formed by
the heat; a fmall quantity of empyreumatic
oil next comes over j and the coaly refidue,
which is light and porous, contains alkali,
and almoft always neutral fait. The extract,
expofed to air, becomes mouldy, and attracts
moifture 5 the fait it contains cryftallizing,

and

ESSENTIAL SALTS. 23

and feparating from the extractive part.
They are often changed, and intirely decom^
pofed. It diflblves in water ; producing the
appearance of a ftrong infufion. Acids de-
compofe this folution, in the fame manner
as they do foaps, and difengage a principle
more or lefs oleaginous. Metallic folutions
likewife feparate this principle, by double
affinity. The chemical properties of extract
have not been farther examined into j but
thofe that are already known, evince, that
it is with great propriety confidered. as a kind
of foap.

Extracts are ufed in medicine as aperitive,
folvent, diuretic, ftomachic, remedies, and
are daily adminiftered with great fuccefs.

CHAP. IV.

EfTential Salts,

^KE faline fubftances, held in folution
A in the juices of plants or the water
wherein they are infufed, are called effential
falts of plants. They are obtained by cool-
ing thofe fluids, which are iirft evaporated to
the confiftence of fyrup. As thefe falts are
impregnated with extractive, and flit matter,
it is neqeflary to purify them with lime and
B 4 whites

24 ESSENTIAL SALTS.

whites of eggs. If thefe falts be of an acid
nature, lime muft not be ufed, becaufe it
would neutralize them, but pure white clay
in powder. After the firft extraction, they
are ftill very impure. Solution in diftilled
water, and cryftallization, may be repeated
till they become pure and white.

The effential falts of plants are of a diffe-
rent nature, and may be diftinguiihed into
two claries.

Class I. Of Effential Salts.

The firft clafs includes thofe which re-
femble mineral falts. The principal fpecies
are, i. Cretaceous fixed alkalis, which are
obtained from almoft all plants, by macerat-
ing them with acids, as MargrafT and Rou-
elle the younger have fhewn. The vege-
table alkali is the moft common, but the
mineral alkali exifts in marine plants. 2.
Vitriolated tartar, or vitriol of pot-afh, in
millefoil, in aftringent and aromatic plants,
in fpurge flax, and in the mark of olives. 3.
Glauber's fait, or vitriol of foda, from tama-
rifk. 4. Nitre, from borage, turnfole, tobac-
co, &c. 5. The febrifuge fait of Sylvius, or
muriate of pot-afh ; and marine fait, or mu-
riate of foda, in marine plants. 6. Selenite
difcovered by Model in rhubarb.

Many other falts will doubtlefs be found,
refembling thofe of minerals, when a greater

number

ESSENTIAL SALTS. 25

number of plants {hall be accurately ana-
lyzed. It has likewife been thought that
volatile alkali; or rather ammoniacal chalk,
exifts ready formed in cruciferous plants ;
becaufe thefe plants, by diftillation, afford
on the firft application of heat, a phlegm
which holds a fmall quantity of that fait in
folution. On this account the ancients
called them animal plants; but Rouelle the
younger has {hewn, that this fait does not
exift ready formed in plants, but is produced
by the re-adlion of the principles, which is
promoted by heat. Mr. Baiime pretended
that the volatile principle of cruciferous
plants is nothing but fulphur. The vola-
tile alkali obtained from thefe plants, arifes
from the inflammable gas of the oil united
to the mephitis contained in the vegetable,
as Mr. Berthollet has {hewn.

Various opinions have been held, refped:-
ing the mineral falts found in plants. Some
have thought, that thefe falts were conduct-
ed from the earth by water, and pafled into
the vegetables without alteration. Others
have fuppofed, that the faline fubftances were
formed by the procefs of vegetation. It is
certain,- that two very different plants grow-
ing in the fame foil, as for example, borage
and millefoil, afford each the fait peculiar
to itfelf , that is to fay, the borage affords
nitre, and the millefoil vitriolated tartar.
A fingle experiment, which has been much

talked

l6 ESSENTIAL SALTS.

talked of, but never accurately made, would
decide the queftion ; namely, to caufe fuch
plants as afford a certain fait, for example,
nitre, to grow in a quantity of earth, pre-
vioufly lixiviated, and to water them with
water containing marine or fome other fait.
If the plants in thefe circumftances afford
nitre, and not marine fait, it might be con-
cluded that the fait does not pafs as fuch in-
to the organs of plants, and that the proper
fait is formed by the procefs of vegetation.

Class II. Of Effential Salts.

The fecond clafs contains fuch falts as
are peculiar to vegetables. Thefe truly effen-
tial falts always confift of an acid united
vnith an alkali, or an oil. The acid is often
in a difengaged ftate, though fometimes
mafked by other fubftances.

The effential acid falts of vegetables are
found in a great number of plants, and arc
afforded, in general, by all thofe which have
a four tafte. Such are forrel, acid fruits,
lemons, oranges, &c. The fait befl known
of this kind in commerce, is called fait of
forrel. It has been long fuppofed to have
been obtained from the aleluia, or oxys, but
it is now affirmed to be really extracted from
a kind of forrel, in many parts of Switzerland,
This fait has the form of white irregular

cryflals^

ESSENTIAL SALTS. 2J

cryftals, of a fharp tafte, and reddens blue
vegetable colours, s

It diifolves readily in water, and may be
cryftallized without lofing its acid. By
heat, in a crucible, it exhales a ftrong acid
fmell, becomes carbonaceous, and takes fire.
Its flame is blue, like that of fpirit of wine,
and leaves, after its combuftion, a white
fait, which with fpirit of fait forms marine
fait. An ounce of this fait afforded Mr. Bau-
me, by diflillation, three drachms and a half
of an acid colourlefs liquor, with a flight
fmell of marine acid. No oil paffed it over ;
the refidue was coaly. This fait precipitates
the nitrous folution of mercury, as does
likewife the acid it affords by diftillation.
The latter, mixed with the nitrous acid,
did not diffolve. Bergman places the acid
of forrel as a peculiar acid, in the thirteenth
column of his table of affinities. He dif-
fers from Baume in certain particulars,
though he agrees with him in mod, as we
(hall obferve ; but he has not faid whether
his experiments were made with the fait of
forrel in commerce, or the true eflential fait
of forrel. The following is an extradt of
his doctrine refpefting this fubftance. Salt of
forrel confifts of the vegetable alkali, fuper-
faturated with a peculiar acid. Scheele has
contrived a very good method of obtaining
this acid fait. He mixed the oxaline acid,
faturated with volatile alkali, with a folution

of

«8 ESSENTIAL SALTS.

of ponderous earth, in the nitrous acid : the
principles of thefe two compounds were
mutually changed by double affinity ; the
ponderous earth uniting with the oxaline
acid, forming the barytic oxate of Mr. De
Morveau, and falling to the bottom, on
account of its difficult foiubility. This pre-
cipitated fait is decompofed by the vitriolic
acid, which has a ftronger affinity with pon-
derous earth than any fubftance hitherto
known. The oxaline acid remains difen-
gaged in the fupernatant liquor, which is
decanted from the ponderous fpar, formed
during the decompoiition. This fait feems
to refemble the acid of fugar, rather than
that of tartar, though it differs from both.
For, when combined with a fmall quantity
of vegetable alkali, it forms fait of forrel,
fimilar to that of tartar ; but which decrepi-
tates in the fire, melts, becomes almoft black,
and capable of being totally decompofed by
chalk : thefe properties are not found in tartar.
A fmall proportion of vegetable alkali com-
bined with acid of fugar, reiembles neither
tartar nor fait of forrel. The oxaline acid
prefers lime to alkalis; but it is yet uncertain
whether ponderous earth and magnefia have
likewife a ftronger affinity to this acid. It
decompofes felenite j becaufe it has a ftronger
affinity than the vitriolic acid with lime.
If the oxaline acid be ftrongly heated, it is
deftroyed j but it neither fwells, nor be-
comes

ESSENTIAL SALTS. 29

comes fo black, as the acid of tartar. By
diftillation, it affords a phlegm, much more
acid than that which is obtained from the
latter by the fame procefs. From thefe cir-
cumftances we may perceive, that the dif-
ference between Bergman and Baume, con-
fills in the former admitting the vegetable
alkali as the bafe of this fait -, whereas the
latter chemift found it to contain fait of foda.
All the acid falts of plants have not yet
been examined, though a great number is
known. The acid of lemons may be fepa-
rated from its mucilage by Handing, and
concentrated by the a&ion of froft, as Mr.
Georgius has ihewn ; or by evaporation,
carefully conducted. It has been thought
analogous to the acid of tartar, though its
ftronger tafte feems to indicate a refem-
blance with the oxaline acid. Stahl affirms
this acid, faturated with crab's eyes, and
digefted with a fmall quantity of fpirit of
wine, gradually affumes the nature of vine-
gar. Bergman obferves, that the acids of
fpar, phofphorus, arfenic, borax, fugar,
tartar, forrel, and lemons, refemble each
other, in being fcarcely at all foluble when
combined with earths ; and that they only
become fo, by means of an excefs of acid ;
a property which is not found in other falts.
Yet felenite and ponderous fpar, two earthy
falts, formed by the vitriolic acid, are fcarcely
foluble in water.

Fruits,

30 ESSENTIAL SALTS.

Fruits, which are at firft four, and be-
come fweet as they ripen, afford a fait,
whofe acid is lefs developed than that con-
tained in the foregoing fubftances. This fait
feems to occupy the middle place between the
very acid eifential falts, and the faccharine
matter, and refembles the tartar of wine.
It is obtained from apples, pears, quinces,
tamarinds, &c. Rouelle the younger, has
examined it carefully in many of thefe vege-
tables. We mall fpeak more largely con-
cerning it when we attend to the fpiritous
fermentation.

Modern chemifts feem inclined to think,
that all the acids of four fruits differ from
each other, and compofe particular fpecies.
Bergman and Scheele are of this opinion.
The latter fucceeded in cryftallizing the acid
of lemons, by faturating the juice with
chalk, and decompofing the fait by the ad-
dition of vitriolic acid ; the acid of lemons
is difengaged in the fupernatant liquor, and
may be obtained in cryftals by evaporation
and cooling. We mail hereafter fee, that
this cryftallized acid differs from lemon
juice, and does not afford the fame refult
with the nitrous acid.

CHAP,

SUGAR. 31

CHAP. V.

Concerning the Saccharine Matter.

THE faccharine matter, which many
chemifts coniider as a kind of eflential
fait, is found in a great number of vegeta-
bles, and may be properly ranged among
their immediate principles. The maple,
the birch, the red beet, the parfnip, the
grape, wheat, &c. contain it. Margraff ex-
traded it from moft vegetables. The petals
of many flowers, and the nedtariums placed
in thofe organs, elaborate a principle of this
kind.

The fugar cane, arundo faccharifera, con-
tains it in larger quantities, and affords it
more readily, than any other plant. The
ripe canes are crufhed between two iron
cylinders, placed perpendicularly. The ex-
preffed juice falls on a plate beneath, and is
called melaffes. It flows into a caldron,
where it is boiled with wood-afhes and lime,
and the fcum taken off. This boiling with
afhes and lime is repeated in three other
boilers, and converts it into fyrup. It is
then ftrongly boiled with lime and alum ;
and when it is fufficiently concentrated, it
is poured into a veffel called the cooler.

When

32 SUGAR*

When it is cooled fo that the finger may be
plunged into it without injury, it is poured
into barrels placed over certain cifterns, and
pierced at the bottom with many holes,
flopped with canes. The fyrup becomes
folid in the cafks, and part flows out through
the holes into the cifterri beneath. The
fugar in this concrete ftate is yellow and
greafy ; it is called mufcovado. It is re-
fined in the fugar iflands by boiling, and
pouring into inverted earthen cones, called
pans. That part of the fugar which is
incapable of becoming concrete, runs through
the aperture of the pan into a pot placed
beneath. The bafe of the fugar loaves is
taken away, and white fugar in powder is
put in its place, and preiTed down ; the
whole is then covered with moiftened clay.
The water of the clay filtrates through the
fugar, and carries with it a portion of the
mother water, which runs out through the
aperture at bottom, and is received in other
pots. A fecond covering of clay is put on
when the firft is dry, and the water is fuf-
fered to filter through a fecond time ; after
which, the loaves are carried to a flove to
dry. At the end of eight or ten days thefe
loaves are broken, and the powdered fugar is
conveyed to Europe, where it is refined in-
to fugar of different qualities.

The procefs of refining confifts in boiling
the fugar in lime-water, together with bul-
locks

SUGAR* 33

locks blood, taking off the fkim three or
four times, and filtering the liquor, which
is then poured into pans to make loaves.
The loaves are covered with a ftratum of
moiftened clay, and the water is thus filter-
ed through the fugar, by the repeated ad-
dition of a new ftratum of clay as the former
becomes dry, until the fugar has acquired
the requifite degree of whitenefs. The
loaves of refined fugar are then conveyed
into a ftove, and at the end of eight days
are wrapped in paper, and tied up for fale.
The remaining fyrup, which cannot be cryf-
tallized, is fold under the name of melafTes.

All chemifls formerly fuppofed, that thefe
different operations feparate a fat matter from
fugar, and by that means render it fufceptible
of cryftallization. Bergman thinks, that
lime ferves to deprive it of that excefs of acid>
which prevents its taking the folid form*
As it is quickly evaporated during the whole
procefs, it takes the form of a granulated
and irregular mafs, in the fame manner as
we have before obferved with refpedt to the
vitriol of zink.

Sugar confifts of a peculiar acid united to
a fmall quantity of alkali, and much fat mat-
ter. It cryftallizes in hexahedral truncated
prifms, and in this ftate is called fugar-candy.
By diftillation, it affords an acid phlegm,
and a few drops of empyreumatic oil. The
refidue is a fpungy light coal, which con-

Vol. IV. C tains

34 SUGAR*

tains a fmall quantity of vegetable alkali.
This fait is inflammable. On hot coals it
melts, and fwells up very much, emits
a penetrating vapour, and becomes con-
verted into a brown yellow matter called
caramel. It is very foluble in water, to
which it gives much confiftence, and con-
ftitutes a kind of mucilage, called fyrup.
Syrup, diluted with water, is capable of fer-
mentation, and affords ardent fpirit.

Bergman has obtained, from all faccha-
rine matters, efpecially fugar, an acid of a
peculiar nature. For this purpofe, one part
of fugar in powder is mixed in a retort with
fix parts of aqua fortis, and a gentle heat is
applied. The evaporation is continued for
fome time after the red vapours have ceafed.
The folution being fuffered to cool, affords
white cryftals in the form of four-fided
needles or prifms, terminated with dihe-
dral fummits. The decanted liquor treated
a fecond time with three or four parts of the
fame nitrous acid, affords, by a new cryftal-
lization, prifms of the fame form. The ope-
ration is again repeated on the fecond mo-
ther water. An ounce of white fugar, by
this procefs, affords about three drachms
of prifmatic fait; which is diffolved in hot
water, and cryftallized by cooling, in order
to obtain it in a ftate of purity.

The acid of fugar has a very penetrating
four tafte. Diluted with water, it forms

aa

SUGAR. 35

an agreeable acid liquor. It reddens all blue
vegetable colours. Expofed to a mild heat,
it becomes opake, and falls into a powder,
refembling efflorefcence, and lofes three-
tenths of its weight, by the evaporation of the
water which enters into its cryftals. This
water may be collected by the ufual apparatus
for diftillation. A ftronger heat fufes the acid,
and gives it a brown colour; an acid phlegm
paffing at the fame time into the receiver,
fimilar in all its properties to the fait itfelf.
Part fublimes in the form of a white cruftj
and the retort contains fcarcely any refidue.
The refidue is grey or brown, and does not
amount, according to Bergman, to more
than the fiftieth part of the original matter.
A very confiderable quantity of a gafeous fub-
ftance is likewife afforded in this operation :
half an ounce of the acid of fugar afforded
Bergman ioo cubic inches of gas, half of
which was cretaceous acid, and the other half
inflammable gas, which burned with a blue
flame. The Abbe Fontana, who repeated
this experiment, obtained from an ounce of
the cryftallized fait, 432 inches of gas, of
which one third was cretaceous acid, and
the reft inflammable gas, mixed with com-
mon air. On repeating the fame experi-
ment, I had a refult nearly agreeing with
that of the latter chemift. The moft Angu-
lar circumftance is, that the fublimed por-
tion diftilled for two more fucceffive times
C 2 affords

36 SUGAR.

affords no coaly matter, but only a refidue of
a whitifh grey colour. This fait heated in an
open fire, emits a very penetrating vapour,
and leaves a reiidue which is perfectly white.

The acid of fugar expofed to the air, ef-
florefces in procefs of time.

Cold water diffolves half its weight of
this fait ; but boiling water diffolves double
the quantity. The fait cryftallizes as it
cools.

The acid of fugar diffolves the bafe of
alum. The evaporated folution affords a
yellowifh, tranfparent, fweet, aftringent,
matter, which becomes moift in the air,
and reddens turnfole. This fait boils up in
the fire, lofes its acid, and leaves the clay
of a brown colour. It is decompofable by
mineral acids.

The acid of fugar, combined with ponde-
rous earth, forms a fait fcarcely foluble,
which affords angular cryftals, when the
acid is in excefs. Hot water, by carrying
off this excefs, renders them opake, pul-
verulent, and infoluble.

When combined with magnefia, it affords
a white fait in powder, decompofable by the
fparry acid, and by ponderous earth.

Saturated with lime, the acid of fugar af-
fords a pulverulent (alt infoluble in water,
and not decompofable but by fire ; becaufe
the affinity of this acid with lime is fuch,
that it takes it from every other. Bergman,

confequently,

SUGAR. 37

confequently, propofes the acid of fugar as
a teft to difcover the prefence and quantity
of lime contained in mineral waters, whe-
ther difengaged, or in combination with
any acid. This fait turns fyrup of violets
to a green.

The acid of fugar unites with the vege-
table alkali, and may be cryftallized, pro-
vided either of the principles be in excefs.
This fait, which is very foluble in water,
is decompofable by the action of fire, and
by the mineral acids.

Combined with two parts of foda, the
acid of fugar forms a fait of difficult folubi-
lity, which dilfolves more readily in hot
than cold water, and turns fyrup of violets
to a green.

With the volatile alkali it affords an am-
moniacal fait, which by flow evaporation,
cryftallizes in quadrilateral prifms decom-
pofable by fire, and convertible into creta-
ceous ammoniacal fait, formed by the de-
ftrudrion of the faccharine acid. f

The acid of fugar is foluble in the mine-
ral acids. It gives a brown colour to oil of
vitriol, and js decompofed by fmoking
fpirit of nitre.

In general, it combines more readily with
metallic calces than with metals.

i. With white arfenic it forms very fufi-
ble, volatile, prifmatic cryftals, decompof-
able by heat.

C 3 2. With

38 SUGAR.

2. With cobalt, a pulverulent fait of a
light rofe colour, and difficultly foluble in
water.

3. With calx of bifmuth, a white fait in
powder, of difficult folubility.

4. With calx of antimony, a fait in cryf-
talline grains.

5. With nickel, a white or greenifh yel-
low fait, of difficult folubility.

6. With manganefe, a fait in a white
powder, which becomes black by heat.

7. With zink, which it diffolves with ef-
fervefcence, it forms a white pulverulent
fait.

8. With calx of mercury, a white pulve-
rulent fait, which becomes black by the
contidt of light. This acid decompofes the
vitriol and nitre of mercury.

9. It at firft blackens tin, which after-
wards becomes covered w^ith a white pow-
der. The fait it forms with this metal is
of an acrid tafte, and by a wrell-condudted
evaporation, cryftallizes in a prifmatic form.
If quickly evaporated, it affords a tranfpa-
jent mafs refembling horn.

10. It tarnifhes lead, but diffolves the
calces much more readily than the metal it-
felf. The faturated liquor depofits fmall
cryftals, which may likewife be obtained by
pouring the acid of fugar into a folution of
the nitre, or the muriate of lead, as well as
into the acetous folution of that metal.

II. It

6UGAR. 39

ii. It attacks iron filings, and produces
inflammable gas. This folution is ftyptic,
and affords prifmatic cryftals, of a greenifh
yellow, decompofable by heat. The faifron
of Mars, united to this acid, prefents a yel-
low powder, fimilar to that which is ob-
tained by pouring the fluid acid cjf fugar into
a folution of martial vitriol.

12. It acts on copper, and completely
dilfolves the calces of that metal, forming a
fait of a light blue colour, and of difficult
folubility. This fait may likewife be ob-
tained by precipitating the folutions of cop-
per in the vitriolic, nitrous, muriatic, and
acetous acids, by the addition of the acid of
fugar.

13. The calx of filver, precipitated by
vegetable alkali, is fparingly dirTolved in this
acid. The beft manner of procuring this
fait, which Bergman calls faccharated filver,
is to precipitate the nitrous folution of this
rnetal by the acid of fugar : a white preci-
pitate is formed, fcarcely foluble in water,
which becomes brown by the contact of
light.

14. This acid has fcarcely any action, an
the calx of gold.

15. Laftly, it diflblves the precipitate of
platina, made by foda. This folution is
yellowifh, and affords cryftals of the fame
colour. Such are the phenomena defcribed

C4 by

40 SUGAR,

by Bergman, refpe&ing the combinations of
the acid of fugar with metallic fubftances.

It may be fuppofed, from the procefs of
this celebrated chemift for obtaining the
acid of fugar, that this fait is produced from
the nitrous acid made ufe of. Bergman does
not think that this opinion is admiffible,
becaufe the acid of fugar has none of the
properties of that of nitre, but on the con-
trary, differs from it in all its combinations.
The nitrous acid does not, in fail, appear
to enter into the acid of fugar ; but the great
quantity of nitrous gas emitted in this pro-
cefs, fhews, that the fpirit of nitre is de-
compofed. Now, fince the nitrous acid,
according to the experiments of M. Lavoi-
fier, does not afford nitrous gas, but in pro-
portion as it lofes the bafe of pure air, it
appears that a part of its oxyginous principle
combines wTith the combuftible matter of
the fugar, to form the acid obtained. We
have (ttn already, that the production of the
arfenical acid, and of the dephlogifticated
muriatic acid, may be explained in this
manner.

Though, at the time of the firft difcovery
of this acid, it was thought that the faccha-r
rine principle was neceffary to its formation,
it is at prefent known, that a great number of
vegetables, which are not faccharine, afford it
in greater or lefs abundance ; fuch are gums,
ilarch, vegetable glutep, fait of forrel, le-
mon

SUGAR. 4X

mon juice, fpirit of wine, and many animal
matters, as Mr. Berthollet has difcovered.
Among thefe fubftances, thofe which pro-
duce the greateft quantity of this peculiar
acid, by the a&ion of fpirit of nitre, are
fuch as do not afford fugar. Pure fugar
did not afford Bergman more than one-third
of its weight of acid ; and Mr. Berthollet
obtained more than half from wool. It
feems, therefore, as M. De Morveau thinks,
that this acid is formed by the union of a
peculiar attenuated oil, which exifts in all
organic fubftances, and is the fame through-
out ; and that confequently the name of
faccharine acid is improper. Mr. Scheele
has obferved, that the acid of lemons, cryf-
tallized by the procefs defcribed in the fore-
going chapter, does not afford faccharine
acid, by treatment with nitrous acid, though
lemon juke itfelf affords it. The vitriolic
acid, employed for the purification of this
acid fugar, feems, therefore, to decompofe
the oil which forms the bafe of the faccharine
acid.

Sugar is very extenfively ufeful. It is a
food which, taken in too large a quantity,
is capable of heating the animal fyftem. It
is very much ufed in pharmacy, where it is
the bafe of fyrups, lozenges, and other pre-
parations. It is very ufeful, as a medium
to favour the folution or fufpenfion of refins,
oils, &c. in water. It preferves the juices

of

42 SUGAR.

of fruits, after they are reduced into a jelly.
It may even be confidered as a medicine,
fince it is incifive, aperient, flightly tonic,
and ftimulant ; and there are, accordingly,
inflances of diforders, arifing from obftruc-
tions, which have been cured by the ha-
bitual ufe of fugar.

Certain juices, which flow out of plants,
have a faccharine tafte. Manna and nedtar
are of this kind. Manna is produced by
the leaves of the pine, the oak, the juni-
per, the willow, the fig-tree, the maplea
&c. The afh, which is very abundant
in Calabria, Sicily, &c. affords the man-
T)a in commerce. It flows naturally from
thefe trees, but is much more abundant-
ly obtained by making incifions in their
bark. That which is collected on chips of
wood, or final 1 flicks, introduced into the
artificial apertures, forms a kind of ftalactites,
peiforated within, and called manna in the
tear. Manna, in flakes, flows on the bark,
and contains fome impurities. The inferior,
unftuous fort, contains many foreign fub-
ftances, and confifts of the refufe pieces of
the two former kinds : it is always moift,
and frequently adulterated. The tafte of
manna is fweet, and flightly naufeous. The
manna afforded by the larch tree, which
abounds in Dauphiny ; and that of the alhagi,
which grows in Perfia, (Hedyfarum Linn.)
in the neighbourhood of Tauris, are not

ufed :

MUCILAGE* 43

ufed : the latter bears the name of tereniabin.
Manna is foluble in water, and affords, by
diftillation, the fame products as fugar.
Treated with lime, and white of eggs, it
affords a fubftance refembling fugar ; and by
the procefs already defcribed with the ni-
trous acid, it affords an acid of the fame
nature as is obtained from fugar.

It is ufed as a purgative, in the dofe of
from one to two, or three ounces ; or in the
dofe of a few drachms, diluted, as an al-
terative.

3S£

CHAP. VI.

Concerning Gum and Mucilage.

ANOTHER kind among the proper
juices of plants, is that called gum, or
mucilage. This fubftance is very abundant in
the vegetable kingdom. It is found in a great
number of roots; the young fhoots, and new
leaves, contain it in large quantities. This
principle may be known by its vifcous and ad-
hefive quality, when thefe parts are crufhed
between the fingers. At the time of the year
when the juices are moft abundant, it natu-
rally exfudes through the bark of trees, and
thickens at the furface into gum. Gum is

foluble

44 MUCILAGE.

foluble in water, to which it gives a thick
and vifcous confiftence. This folution,
known by the name of- mucilage, becomes
dry, tranfparent, and brittle, by evapora-
tion.

Gum burns without any fenfible flame;
it melts, and boils up on hot coals ; by dis-
tillation, it affords much acid phlegm, a
fmall quantity of thick and brown oil, and
cretaceous acid, in the ftate of elaftic fluid.
Its coal is very bulky, and contains a fmall
quantity of the fixed vegetable alkali.

Three kinds of gum are ufed in medicine,
and in the arts.

i . Gum, which flows from the apricot,
pear, plumb trees, &c. It is white, yellow,
or reddifh ; and when well felefted, may be
applied to the fame ufes as other gums. A
kind of gummy juice, of a beautiful yellow
colour, flows from the elm, and is fome-
times fnund in confiderable quantities on its
bark. I find this gum to be infipid, foluble,
vifcous, and to poffefs all the characters of
juices of this nature.

2. Gum arabic, which flows from the
acacia in Egypt and Arabia. Gum fenegal
is of the fame nature : it is ufed in medicine
as a foftening and relaxing remedy ; it gives
confiftence to crayons, and is ufed in feveral
arts.

3. The gum tragacanth, which flows from
the adragant of Crete; tragacantha cretica.

It

MUCILAGE. 45

It is adminiftered in the fame cafes as th
foregoing. Its folution is fomewhat thicker
and it requires more water to diffolve it than
the other gums. Vifcous flakes are depo-
fited from its folution.

Mucilages, of the fame nature as gums,
are obtained from many plants. The roots
of mallows, the greater comfrey, the bark of
elm, linfeed, the feed of quinces, &c. afford
vifcous fluids, by maceration in water,
which, by evaporation, leave true gums.
The deco&ion of thefe plants is fubftituted,
in medicine, inftead of gums.

All thefe fubftances, chemically confider-
ed, feem, at firft fight, to be bodies not much
compofed, fince chemical experiments often
exhibit fubftances, which, by their gelati-
nous form, feem to refemble gums and mu-
cilages. Yet, from thefe vegetable products,
which feem to conflitute an excrementitious
humour, are obtained water, liquid acid,
cretaceous acid, an oily principle, and fixed
alkali, united to a coaly refidue. This re-
fidue contains likewife a fixed earth, whofe
nature is not yet known.

When gums and mucilages are treated
with the nitrous acid, they afford a cryftal-
lized acid, of the fame nature as that which
is improperly called acid of fugar. It ap-
pears, therefore, that they contain the oily
principle, whofe combination with the oxy-

ginous

46 MUCILAGE.

ginous principle conftitutes this fpecies of
acid.

The analogy between mucilage and faccha-
rine matters, is likewife obfervable in the
fumes of burned gum, which in fmell refem-
ble that ofyalomel, as well as by the nature
of the produces both afford by diftillation,
and the poroiity and lightnefs of their refidual
coal. Among fruits which become faccharine,
there are fome, as for example, apricots, pears,
&c. from which, before the time of their
maturity, a true gum exfudes. The kind
of dry mucilage, which we fhall hereafter
defcribe, under the name of amylaceous fe-
cula, is converted into faccharine matter by
germination. Thefe fafts, and many others
which might be urged, fhew, that there is
a ftrong refemblance between fugar andgilm.
The inlipid and gummy mucilage may per-
haps pafs to the ftate of fugar, by a kind of
fermentation. If the fad: were eftablifhed,
it would be proper to place this fermentation
before that which Boerhaave has diftin-
guifhed by the name of fpirituous ; and it
would always precede it, whether in the
procefs of vegetation, or in thofe operations
which are artificially made to produce the
faccharine tafte in barley, &c.

CHAP.

oils. 47

CHAP. VII
Of Fat Oils.

O

ILS are proper juices of a fat and
unftuous nature, either folid or fluid,
indiffoluble in water, combuftible with flame,
and volatile in different degrees ; they are
contained in the proper veflels, or in pecu-
liar veficules. Thefe fubftances are found
in two ftates in vegetables ; either combined
with other principles, as in extracts, muci-
lages, &c. or at liberty. Our attention mult
at prefent be directed to the latter.

Chemifts have fuppofed the exigence of
a fimple oily principle, as well as of a pri-
mitive fait. This oily principle, combined
with different fubftances, and modified by
thefe combinations, conftituted, according to
them, the different fpecies of oils obtained
in the analyfis of vegetables. The charac-
ters attributed to this fimple and primitive
oil, were great fluidity and volatility, neither
colour nor fmell, combuftibility with flame
and fmoke : it was faid to be incapable of
uniting with water, and to confift of an acid
combined with an earth and phlogifton.

It

4S FAT OILS.

It is certain that oil?, in their decompofi-*
tion, always afford a fmall quantity of acid,
and much inflammable gas ; the earth forms
but a fmall part, as they leave but an incon-
fiderable quantity of fixed and coaly refidue.
This notion refpe&ing the oily principle,
mull; be confidered as a mere hypothefis.

Oils are never formed but by organic
bodies, and all fubftances in the mine-
ral kingdom, which prefent oily characters,
have originated from the acftion of vegetable
or animal life. It is even very probable,
that they are only formed in vegetables, and
that they pafs without alteration into animal
fubftances.

The oily juices of vegetables are diftin-
guifhed into fat oils and effential oils.

Fat oils are very undtuous ; their tafte is
commonly mild and infipid, and they have no
fmell ; they are not volatilized but by a heat
fuperior to that of boiling water, and do not
take fire till heated fufficiently to volatilize
them. The wick which is ufed to burn fat
oil in lumps, anfwers this purpofe ; it heats
the oil to fuch a degree, as volatilizes it.

Moft fat oils are fluid, and require a con-
fiderable degree of cold to congeal them ;
others become folid by a very flight degree
of cold ; and others again are almoft always
folid : thefe laft are called butters.

Fat oils are not emitted from the furface
of vegetables, but are contained in~the ker-
nels,

FAT OILS. 49

ncls, the pippins, and emulfive feeds* They
are extracted by breaking the cellules by
which they are enclofed $ that is to fay, by
pounding and preffure.

Fat oils expofed to air are changed, and
become rancid ; their acid becomes develop-
ed, and they lofe their properties, at the
fame time acquiring others, by which they
more nearly refemble effential oils. \ Water
and fpirit of wine, by warning off this dif-
engaged acid, deprive them of their ftrong
talTe, but never reftore their original ftate.

Mr. Berthollet has difcovered> that fat
oils thinly fpread on the furface of water,
and expofed to the air, become thick, and
refemble wax. This appears to arife from
the abforption of the bafe of vital air.

By diftillation they afford an acid phlegm of
a penetrating fmell, a light oil, adenferoil, and
a large quantity of inflammable gas mixed with
cretaceous acid. The quantity of refidual
coal is not abundant. By rediftilling thefe,
more phlegm, and an oil which becomes light-
er each time, are obtained. This is known
by the name of philofophical oil ; the alche-
mifts prepared it by diftilling, for feveral fuc-
ceflive times, an oil with which they had im-
pregnated a brick. It is not exactly known
how far this decompofition may be carried,
though it is faid that fat oil may this way
be reduced into the difengaged inflammable
principle, acid, phlegm, air, and earth.
Vol. IV. D Water

Founded 1813 II

So ^J/AT OILS.

Water docs not produce any change in
fat oils in the cold, but it purifies them, by
carrying off part of their mucilage, which
is likewife precipitated during their com-
buftion, and is thecaufe of their property of
fermenting and becoming rancid. It is well
known, that water thrown on burning oils,
caufes them to give a ftronger flame, inftead
of extinguishing them. This depends on
the vital air afforded by the decompofition
of the water, which affords the bafe of vital
air. When the vapour of the flame of
burning fat oil is collected in a chimney,
terminated by a worm pipe, a large quan-
tity of water is obtained : whence it fol-
lows, that this immediate principle of vege-
tables contains an aqueous inflammable gas.

Fat oils do not combine with filiceous
earth : with clay they form a foft pafte ufed
in chemiftry, by the name of fat lute.

By particular procefTes they combine with
magnefia, which reduces them to a faponace-
ous ftate.

Lime unites with oils, but not in a very
evident manner when the fubftances are
immediately applied to each other.

Pure alkalies combine readily with fat
oils, and produce a compound called foap.

To prepare this compound, oil of olives,
or of fweet almonds, is triturated with a
concentrated lixivium of foda, rendered cauf-

tic

FAT OILS. 51

tic by lime, and known by the name of foap
lye. The mixture becomes thick in a few*
days, and is converted into the foap ufed in
medicine. The foap of commerce is made
by boiling the lixivium with rancid oil ; it
is then white, but is marbled by martial
vitriol. Green foap is made with the marc
of olives and pot afh.

Soap is foluble in pure water : heat de-
compofes it, and difengages phlegm, oil*
and volatile alkali produced from the fix-
ed alkali and the oil ; the coal contains
much fixed alkali. This artificial compofi-
tion of volatile alkali feems to prove, that
fixed alkalies contain mephitis, which re-
acts on the inflammable gas of the oil.

Lime-water decompofes foap, according
to the obfervation of Mr. Thouvenel ; an
infoluble calcareous foap is then formed,
which is depofited in grains. Acids poured
on foap difengage the oil, but fomewhat
altered.

The volatile alkali does not combine with
fat oils without difficulty; yet, by long
trituration the mixture becomes opake, and
rather more conliftent.

Fat oils unite with acids, and form pecu-
liar foaps, when the acid made ufe of is
weak. Meiirs. Achard, Cornette, and Mac-
quer, have made experiments refpecting thefe
compounds. Mr. Achard added concentrat-
ed vitriolic acid, by fmall portions, to fat oil.
D a This

$2 FAT OILS.

This mixture being continually triturated,
becomes at length converted into a brown
mafs, foluble in water and fpirit of wine.
The oil obtained from this foap by alkalies,
as well as by diftillation, is always more or
lefs concrete. Mr. Macquer advifes, in
making this foap, to pour the acid on the
oil ; but he obferves, that an acid foap made
in this manner, is fcarcely foluble in water.
The foap which is prepared by triturating
common alkaline foap with oil of vitriol, is
more foluble. The concentrated vitriolic
acid renders fat oils black, and caufes them
to refemble bitumens. This phenomenon
appears to arife from the re-aftion of the in-
flammable gas of the oil on the oxyginous
principle of the vitriolic acid.

The fuming nitrous acid immediately
changes fat oils to a black colour, and in-
flames fuch as are of a drying nature. Thofe
which do not dry cannot be inflamed, but
by a mixture of fpirit of nitre and oil of
vitriol, as P.ouelle the elder has fhewn in his
Memoirs on the Inflammation of Oils, print-
ed among thofe of the Academy for the
year 1747.

The muriatic and cretaceous acids, act but
weakly on fat oils ; the former, however,
in a concentrated (late, combines with them
to a certain degree, according to Mr. Cor-
net. The dephlogifticated muriatic acid
thickens them much, and appears, by the

abforption

FAT OILS. 53

abforption of its oxyginous principle, to
convert them into a fubftance nearly refem-
bling wax.

The action of the other acids on fat oils,
is not known ; thefe oils do not appear to
combine with neutral falts. Many of the
latter, more efpecially the calcareous falts,
decompofe alkaline foaps. In this decom-
pofition, efpecially that effected by the vi-
triols of lime and magneiia, which are fre-
quently contained in water, the vitriolic
acid unites with the fixed alkali of the foap,
and forms vitriol of foda ; the lime or the
magnefia combines with the oil, and forms a
kind of foap fcarcely at all foluble, which
floats in whitifh curd-like maffes on the fur-
face of the water. This is the caufe of the
common appearance produced by hard waters,
when attempts are made to ufe them with
foap.

The action of inflammable gas on fat oils
has not yet been examined.

Fat oiis diffolve fulphur in a boiling heat,
and this folution is of a deep brownifh red
colour, of a very fetid fmell, and gradually
depofits fulphur in the cryftalline form.
When this combination is diftilled, the ful-
phur is totally decompofed, and is no where
found. This experiment well deferves.to be
carefully repeated. Sulphureous gas is like-
wife obtained in this decomposition.

D 3 Fat

54 FAT OILS,

Fat oils do not appear capable of uniting
with pure metallic fubftances, excepting
copper and iron, on which they have a coa-
fiderable action. But they combine with
metallic calces, and form thick, concrete
combinations, of a foapy appearance, as may
be obferved in the preparation of unguents
and plafters. Thefe preparations have not
yet been chemically examined'; it is only
known, that certain metallic calces are re-
duced in the formation of plafters ; as for
example, the calces of copper and lead, &c.
In docimaftic operations, fat oils are ufed to
reduce metallic calces. Mr. Berthollet de-
fcribes an ingenious and fimple procefs,
for immediately combining a fat oil with
any metallic calx, in the faponaceous form.
It confi'fts in pouring a folution of foap into
a metallic folution ; the acid of the latter
feizes the fixed alkali of the foap, and the
metallic calx is precipitated in combination
with the oil, to which it communicates its
colour. In this manner a beautiful green
foap is formed with vitriol of copper, and
a brown foap with vitriol of iron ; thefe
compounds may perhaps be ufeful in paint-
ing. M. Scheele has difcovered, that by
combining oil of fweet almonds, of olives,
of rape, or of linfeed, with the calces of
lead, and adding a frnall quantity of water
to the mixture, a fubftance is feparated,
which he calls the fweet principle. By

evaporating

FAT OILS. $5

evaporating the water, this principle is ob-
tained, of the confidence of fyrup ; by a
ftrong heat it takes fire ; part is volatilized
in the diftillation without burning; the refi-
dual coal is very light. The fweet principle
does not cryftallize, nor does it appear fufcep-
tible of fermentation; nitrous acid diftilled
four times from it, produces acid of fugar.
This principle appears to be a kind of muci-

Iase-

Fat oils diflblve bitumens, and in particu-
lar amber, but they require the afiiftance of
heat. Thefe combinations are a kind of fat
varnifh, which does not become dry with-
out difficulty.

Fat oils may be diflinguifhed into three
genera.

The firfl comprehends pure fat oils, which
congeal by cold, thicken flowly, form foaps
with acids, and do not take fire by the ni-
trous acid, unlefs oil of vitriol be likewife
ufed. t

i. Such are oil of olives obtained from
the pulp of that fruit, crufhed between two
mill-ftones, and prefled in facks made of
rufhes. The firfl produd: is called virgin
oil ; that which is obtained from the marc,
moiftened with water, is lefs pure, and ip
fits a fediment. The oil of unripe olives
is the oleum omphacine of the ancients.
Oil of olives freezes at 10 degrees below
zero, on Reaumur's thermometer, or ten de-
D 4. grees

56 FAT OILS.

grees and a half above zero, in the thermo-
meter of Fahrenheit, and does not become
rancid in lefs than about twelve years.

2. Oil of fweet almonds extracted with-
out heat, becomes quickly rancid -, it does
not freeze till its temperature is reduced
to 6 degrees below o of Reaumur's fcale,
or 17 and a half of Fahrenheit.

3. Oil of rape obtained from the feeds of
a kind of cabbage called colfa.

4. Oil of ben, extracted from the ben
nut, from Egypt and Arabia; it is very
acrid, inodorous, and freezes very eafily.

The fecond genus comprehends drying
oils, which foon become thick, do not con-
geal with cold, are inflamed by the nitrous
acid alone, and form a kind of refin with
vitriolic acid.

1. Such are linfeed oil, obtained by pref-
fure from linfeed. It is ufed in oily var-
nifhes, and in painting.

2. Nut oil applied to the fame ufe.

3. Oil of poppy feeds, which is not at
all narcotic, as the Abbe»Rozier has clearly
fhewn.

4. Oil of hemp feed, which is very
drying.

In the third genus we comprehend con-
crete fat oils, or butters, among which we
may diftinguifh the following.

I. Butter of cocoa, obtained from the
chocolate nut : four fpecies of cocoa are

diftinguiflied 1

FAT OILS. 57

diftinguifhed ; the large and fmall caracca,
the berbice, and that of the iflands. The
butter is extracted by roafting and fubfequent
ebullition in water, and is purified by melting
with a gentle heat.

2. The cocoa nut affords a butter of the
fame kind.

3. The wax of vegetables is of the fame
kind, excepting that it is more folid ; it
comes from China, where it is made into
yellow, green, or white candles, according
to the manner in which the wax is extracted.
The catkins of birch and poplar, afford a
fmall quantity of this kind of wax. That
of Louifiana is more abundant ; M. Berthol-
let quickly bleaches it with the dephlogifti-
cated marine acid.

The ufe of fat oils in the arts, and in me-
dicine, is very extenfive. They are medi-
cally prefcribed as relaxing, foftening, and
laxative remedies ; fome are even purgative,
as the oil of Ricinus, or PalmaChrifti, which
has been likewiie difcovered to poffefs the
property of deftroying and evacuating the
folitary worm. They enter into many me-
dical compounds, fuch as balfams, unguents,
plafters, &c. they are often ufed as food, on
account of the mucilage they contain.

C H A P.

5S ESSENTIAL OILS*

CHAP. VIII.

Concerning Effential Oils.

ESSENTIAL oils differ from fat oils,
by the following characters : Their
fmell is ftrong and aromatic : Their vo-
latility is fuch, that they rife with the
heat of boiling water : and their tafte is
very acrid. They are likewife much more
combuftible than the fat oils. Thefe oils
exift in moft ftrong fmelling plants. They
are either contained in the whole plant, as
in the Bohemian angelica, or in the root
only, as in ftarwort, the iris, the white
dittany, and the kidney-wort, &c. ; or in
the ftem, as in the woods of fandal, faffa-
fras, pine, &c. or in the bark, as in cinna-
mon. In fome, the leaves only contain it,
as is obferved in balm, peppermint, worm-
wood, &c. in other plants it is found in
the calices of the flowers, as in the rofe, and
lavender. The petals of camomile and
orange flower abound with it. In others
again, it is contained in the fruits, as in
cubebs, pepper, juniper berries, &c. Laftly,
many vegetables contain this oil in their
feeds, as nutmeg, anife, fennel, and mofl
umbelliferous plants. Eflential oils differ

from

ESSENTIAL OILS. 59

from each other, i. In the quantity, which
greatly varies according to the ftate or age
of the plant, 2. In confidence : fome are
very fluid, fuch as thole of lavender, blue,
&c. ; others congeal by cold, as the oils of
anifeed, or fennel; others again are always
concrete, as thofe of rofes, parfley, kidney-
wort, and ftarwort. 3. With refpedt to co-
lour : fome are colourlefs, others yellow, as
that of lavender; others deep yellow, as
that of cinnamon; others blue, as that of
camomile ; others fea-green, as that of
St. John's-wort; or green, as that of parfley.
4. By their weight : fome float on water,
as mod of the oils extracted from plants
growing in temperate countries ; others,
as thole of faflafras and carraway feeds, and
moft oils from hot countries, link to the
bottom. This property is not, however,
conftant with refpeft to climates, the eflen-
tial oils of nutmeg, pepper, and mace, be-
ing lighter than water. 5. With refpeci to
fmell and tafle : this laft property is often
very different in the eflential oil from that
of the plant. . For example, pepper affords
a mild oil, and the oil of wormwood is not
bitter.

Eflential oils are obtained, 1. By pref-
fure, from the cedra, from bergamot, from
lemons, oranges, &c. 2. By diftillation.
For this purpofe, the plant is put into a
copper alembic, together with water ; the

water

60 ESSENTIAL OILS.

water being made to boil, comes over toge-
ther with the oil into the receiver, and is
obtained feparate by decantation.

Effential oils are adulterated either by the
addition of fat oils, which may be known
by the ftain fuch oils make on paper ; or by
oil of turpentine, which may be diftinguifh-
ed by its ftrong fmell, that remains after
the effential oil is evaporated. The addition
of fpirit of wine in moft cafes difcovers the
adulterating fubftance which remains undif-
folved, while the oil unites with the fpirit.

Effential oils lofe their fmell by a gentle
heat, as they are very volatile ; fire alone
does not decompofe them. When heated
with contaft of air, they quickly take fire,
and emit a very thick fume, which becomes
condenfed into a fine and light coaly mat-,
ter : they leave very little fixed coal after
their inflammation ; becaufe they are fo vo-
latile, that the coaly matter is formed in
the part which rifes.

By eypofure to the air they become thick,
and in procefs of time affume the character
of refin. Needle-formed cryftals are depo-
fited fimilar to thofe afforded by camphire
when fublimed. Geoffroy the younger, ob-
ferved them in the effential oils of mother-
wort, marjoram, and of turpentine. The
fame chemift obferves, that their fmell is
fimilar to that of camphor.*

They unite difficultly with lime and alka-

lis5

« See the Memoirs of the Academy for the year 1721.

CAMPHOR. 6l

lis, and are changed by acids. The con-
centrated vitriolic acid concerts them into
bitumens ; but if it be weak, it forms a
kind of foap. The nitrous acid caufes
them to burn: into flame ; the muriatic acid
renders them faponaceous ; and the dephlo-
gifticated marine acid thickens them.

They have no action on neutral falts.

They combine very readily with fulphur,
and form compounds, called balfams of ful-
phur, in which the fulphur is fo far changed,
that it cannot be again recovered.

Mucilages and fugar render them foluble
in water.

They are ufed as cordial, ftimulant, anti-
fpafmodic, &c. remedies. Externally ap-
plied, they are powerfully antifeptic, and
ftcp the progrefs of caries in the bones.

CHAP. IX.

Concerning the Camphorate Principle.

/^Amphor is a white concrete cryftalline
^-* matter, of a ftrong fmell and tafte,
which refembles effential oils in fome of its
properties, and differs from them in others.

From a number of obfervations, chemifts
confider camphor as an immediate principle
of vegetables, exifting in all very odorife-
rous

6z CAMPHOR.

rous plants, that contain effential oil. It

has been obtained from the roots of zedoary,
thyme, rofemary, fage, and other labiated
plants, either by diftillation or decoction, as
Cartheufer and Neumann have obferved; but
this camphor is in final 1 quantities, and
always has the fmell of the plant from which
it is obtained. This lingular fubftance
feems to be combined with the effential oils
of vegetables, as we may conclude from
the obfervation of Geoffroy, mentioned in
the foregoing chapter. M. Joffe, apothe-
cary at Paris, fhewed me a true camphor
obtained from the roots of ftarwort. Lorry
confidered camphor as a principle abound-
ing in vegetables, and placed its fpiritus
rector at the head of a clafs of very power-
ful frnells, whofe effects on the animal eco-
nomy deferve the attention of chemifts and
phyficians.

The camphor ufed in medicine, is obtained
from a fpecies of laurel which grows in China,
Japan, and in the iflands of Borneo, Suma-
tra, Ceylon, &c. The tree which produces
it, fometimes contains fo large a quantity
that it need only be cleft, in order to obtain
very pure tears of camphor, of confiderable
fize. It is obtained by diftillation. The
roots, or other parts of the tree, are put in-
to an alembic with water, which is covered
with a capital, containing ropes of rice ftraw.
On the application of a fufficient heat, the

camphor

CAMPHOR. 63

camphor is fublimed in fmall greyifh grains,
which are afterwards united into larger maf-
fes. This crude camphor is impure ; the
Dutch purity it by fublimation, after pre-
viously adding an ounce of lime to each
pound of the camphor.

Camphor is much more volatile than ef-
fential oils and fubftances : with the moft
gentle heat, it crystallizes in hexagonal la-
mina?, attached to a middle ftem. By a
fudden heat it melts before it rifes. It does
not feem decompofable by this means ; yet
if it be repeatedly diftilled, it affords a red-
diSh and manifestly acid phlegm, which
feems to (hew that the whole might be de-
compofed by repeating the operation a fuffi-
cient number of times. The temperature
of the air in fummer volatilizes it, fo that
it is intirely diffipated. In a clofe veSTel it
fublimes in hexagonal pyramids, or polygo-
nal cryftals, which were obferved and de-
fcribed in the year 1756, by Romieu. Its
fmell is Strong and infupportable to fome
perfons ; it takes fire readily, burns rapidly
with much fmoke, and leaves no carbona-
ceous relidue.

It does not diffolve in water, to which,
neverthelefs, it communicates its fmell : it
burns on the furface of water. Romieu has
obferved, that fmall pieces of camphor, of
the third or fourth part of a line in diame-
ter, on the furface of a glafs of pure water,

have

64 CAMPHOR*

have a rotatory motion, and are diflblved in
the fpace of half an hour. He fufpects that
this motion is produced by electricity, and
obferves that it ceafes when the water is
touched with a body that conducts electri-
city, fuch as an iron wire ; and that on
the contrary, it continues, though the wa-
ter be touched with an infulating fubftance,
fuch as glafs, refin, fulphur, &c.

Earths, the falino-terreftrial fubftances,
and alkalis, have no action on camphor. It
muft, however, be obferved, that experi-
ments have not yet been made with the
cauftic alkalis.

Concentrated acids diflblve camphor. Oil
of vitriol, affifted by heat, difiblves it, and
becomes red. The nitrous acid difiblves it
without any inteftine motion, and forms a
yellow liquid, which, becaufe it floats on
the acid, has been called oil of camphor.
Thfe muriatic acid, in the ftate of gas, dif-
folves camphor j as do likewife the fulphu-
reous and fparry gafes. If water be added
to thefe folutions, they become turbid, and
the camphor is feparated in flocks, which
float on the fur face of the liquid, and does
not appear to have fuftained any change in
its properties. Alkalis, and alio the falino-
terreftrial fubftances, and metallic matters,
likewife feparate camphor from acids.

Neutral falts have no action on camphor.
The action of fulphur and bitumens on this

fubftance

CAMPHOR. 65

fubftance is not known, though it is pro-
bable they would unite with it.

Fat oils, and eflential oils, diflblve cam-
phor by the affiflance of heat. Thefe fo-
lutions, by cooling, gradually depofit cryf-
tals in a vegetation fimilar to that which is
formed in folutions offal ammoniac; namely,
a middle ftem, in which very fine horizon-
tal threads are inferted. This kind of
feathers, examined by the magnifier, is
very beautiful and regular. Romieu was
the firfl who obferved this beautiful crys-
tallization (Memoirs of the Academy for
1756, page 448}. We fhall hereafter fee
that the folution of camphor in fpirit of
wine, which is much better known and
more ufed than the foregoing, prefent-
ed this obferver with a cryftallization fome-
what different, which he obtained by a
peculiar procefs. Camphor is one of the
moft powerful remedies the art of medicine
pofiefles. It difiipates inflammatory tu-
mours in a fhort time, by external applica-
tion. It is ufed as an antifpafmodic, and as
an antifeptic remedy in contagious diforders,
putrid fevers, and in general, in- all difor-
ders which are attended with nervous affec-
tions, or putridity. It is not adminif-
tered in France in larger dofes than a few
grains ; in Germany, and in England, it is
given in the quantity of feveral drachms per
day. It is of importance to be known, that

Vol. IV. E camphor

66 SPIRITUS RECTOR.

camphor often mitigates heat and pain in
the urinary paflages, as it were by inchant-
ment. It is given, triturated with yolk of
eggs, fugar, gums, or in the ftate of oil of
camphor ; and is fometimes ufed in the
compofition of diet drinks. Surgeons ufe
camphorated fpirit of wine, whofe com-
pofition we {hall hereafter defcribe, in exter-
nal gangrenes, and often with good fuccefs.

B

CHAP. X.

Concerning the Spiritus Reclor.

Oerhaave gave the name of fpiritus rec-
tor to the principle in which the fmell
of plants refides. The properties of this
fingular fubftance, fo interefting on account
of its effects on the animal economy, are
yet but little known. The fpiritus rector
appears to be exceedingly volatile, fugacious,
and attenuating. It is continually difengaged
from plants, and forms an odoriferous
atmofphere around them, to a greater or
lefs diftance. All plants differ from each
other in the quantity, efficacy, and nature
of this principle. Some contain it in great
abundance, and are only in part deprived of
it by drying, fo that in thefe it appears to

poffefs

SPIRITUS RECTOR; 67

poflefs a certain degree of fixity. Such, in
general^ are the odoriferous woods, and all
the dry and ligneous parts of ftrong- fmell -
ing vegetables. In others, this principle is
fo volatile and tranfient, that though they
have much fmell, the fpiritus redlor carl
fcarcely be retained, even with the greateft
difficulty. Laftly, there are plants, which
have a fmell fcarcely fenfible ; thefe are call-
ed inodorous, and their fpiritus redtor has
been diftinguifhed by the appellation her^*
baceous.

The flighteft heat is fufficient to difengage
the fpiritus re&or of plants. To obtain this
principle, the plant muft be diftilled in a wa-
ter-bath, and the vapours received in a head,
which being kept cool, may condenfe them,
and caufe them to pafs into the receiver in a
liquid form. This produft is a limpid wa-
ter, charged with the principle of fmell, and
is called the effential, or diftilled water of
the plant. The odorous principle is more
volatile than the fluid which holds it in fo-
lution. Heat drives off the fpiritus rector,
and the liquid becomes, of courfe, deprived
of its peculiar fmell; expofure to air pro-
duces the fame effedt, very light mucilaginous
flocks being depofited, and the fmell of the
fluid being changed to that of mouldinefs.

The principle of fmell unites with the oily
juices, and even feems to be one of the com-
ponent parts of effential oils j for, i . They
E 2 always

68 SPIRITUS RECTOR.

always abound with it. 2. Plants which
have a permanent fmell, conftantly afford
more effential oil than thofe whofe principle
of fmell is very volatile, and which often
afford no effential oil, as is the cafe with
liliaceous plants. To retain the fpiritus
rector of thefe laft, as the lilly, the jeffa-
mine, the tuberofe, it is neceffary to com-
bine them with fat oil. Thefe flowers are
placed in a cucurbit of tin, together with
cotton foaked in the oil of ben : the flowers
and the cotton are difpofed flratum fuper
ftratum ; and the cucurbit being clofed, a
gentle heat is applied. The fpiritus rector
is difengaged, and combining with the oil,
becomes durably fixed. 3. Plants which
have no fmell, do not afford the fmalleft
quantity of effential oil. 4. Vegetables,
whofe fpiritus rector has been extracted
by diftillation in the water-bath, no longer
afford effential oil, or at lead they do not,
unlefs the diftillation has been fo managed,
that they ftill retain part of their fmell ; in
this cafe, they may afford a very fmall
quantity. 5. An effential oil, which has
loft its fmell, refumes it very readily, with
all its properties, when re-diftilled from a
frefh plant, of the fame kind as that from
which it was originally extracted.

The action of faline fubftances on the
fpiritus rector has not yet been examined.

The nature of this principle is not iden-
tical,

SPIRITUS RECTOR. 69

tical, but it feems to differ, according to the
genera of the plants from which it is obtained.
Macquer is of the fame opinion with Boer-
haave, that it is in general compofed of an
inflammable and a faline fubftance ; but he
obferves, that it fometimes participates more
of the faline nature, and in other plants is
more oily. The fpiritus rector of cruci-
ferous plants appeared to him to be faline ;
and he gives it the character of being pene-
trating, without affecting the nerves. That
which, on the contrary, is iniipid or ftrong,
without a keen and penetrating fmell, and
affects the nerves in fuch a manner, as either
to produce or mitigate thofe fymptoms which
depend on their irritation, as is the cafe with
aromatic and narcotic plants, participate
more of the nature of oils, according to that
celebrated chemift. Several facts may be
brought in fupport of this affertion. The
fraxinella emits an odour that forms an in-
flammable atmofphere around the plant,
which immediately takes fire on the approach
of an ignited fubftance : the vapour then
burns from the bottom to the top of the
ftem which fupports the flowers. The fpi-
ritus rector of fraxinella appears, there-
fore, to be of an oily nature. Venel, a
chemift at Montpellier, and difciple of Rou-
elle, obtained an acid fpiritus rector from
favory (marum) by a gentle heat ; and
Roux, profeffor of chemiftry in the fchools

E 3 of

JO SPIRITUS RECTOR.

of medicine, who examined this product,
difcovered, that it does not redden blue ve-
getable colours, but that it faturates alkalis.
Chemifts are not agreed concerning the na-
ture of the fpiritus re&or of cruciferous
plants. Some think that it is acid, and
others imagine it to be alkaline. From the
experiments of Meffrs. Deyeux and Baume,
it appears, that fulphur is found combined
with the odorous principle of antifcorbutic
plants \ and that this combuftible fubftance,
in the ftate of an elaftic fluid, conftitutes
the fpiritus redlor of cruciferous plants.

Two important confiderations remain to
be offered concerning the fpiritus redlor.
The firft is, that this principle, according
to the very probable conjecture of Macquer,
is probably a gas of a peculiar nature. Its
inviiibility and volatility, the manner in
which it is expanded and difperfed in the
atmofphere, together with certain experi-
ments made by Dr. Ingen-houfz on the
noxious gas afforded by flowers, render this
opinion very probable. It only remains,
therefore, to make the proper experimental
inquiries on this fubjeft, which it muft be
conferled require the greateft care and accu-
racy, but at the fame time promife to re-
ward the inquirer with difcoveries of the
moft important kind. Boyle has already
opened an immenfe field, and his labours
have been continued with the greateft fuc-

cefs

SPIRITUS RECTOR. Jl

cefs by Lorry. This philofopher has at-
tended to the alterations which arife from
the mixture of odours, and the changes they
undergo by fermentation, by the adlion of
fire, of air, or of different menftrua. We
cannot, without departing too far from our
original plan, enter into any detail of his
experiments, and {hall therefore only ex-
hibit his primitive divifion of odours. Lorry
divides thefe bodies into five claffes, to which
all other odours may be referred ; namely,
camphorated, etherial, poifonous or nar-
cotic, acid, and alkali. This phyfician, ex-
plaining the bafis of his divifion, eftablifhed
on the effects of odours on the fenfe of
fmelling, and the nerves in general, affirms,
that he does not propofe to inquire into their
chemical nature; but it is moft probable, as
he himfelf thinks, that the chemical pro-
perties of each clafs refemble each other, as
well as thofe properties they exhibit in rela-
tion to the animal economy.

The fecond confideration, with which we
fhall terminate our hiftory of the principle
of fmell, is, that though the plants called
inodorous are confidered as not poiTeffing
it, it is neverthelefs well afcertained, that
by the loweft heat of a water-bath, thefe alfo
afford a fluid, whofe fmell, though feeble,
is fufficient to difcover the plant from which
it was diftilled. I can affert, from many
experiments, that plants, reckoned moft
E 4 inodQrous4

72 SPIRITUS RECTOR.

inodorous, afford, by the water-bath, a dif%
tilled water, which emits their proper odour,
in fuch a manner as to diftinguifti them per-
fectly from each other. Thefe waters are
quickly decompofed, lofing their faint cha-
racterise fmells, and becoming changed by
fermentation, which difcovers acid or alka-
line characters, according to the nature of
the fubftance.

The art of the perfumer con lifts in ex-
tracting the odorous principles of vegetables,
and in preferving or fixing them in different
fubftances. Moftof the proceffes of this art
are intirely chemical.

Diftilled waters are much ufed in the art
of medicine; they po fiefs different virtues,
according to their refpective nature. Thofe
only are ufed which are diftilled by a naked
fire, with the addition of water, as is done
in the extraction of effential oils. We may
obferve, that this manipulation is advifable
in making aromatic effential waters, but is
defective with refpect to fuch plants as are
commonly called inodorous. We are of
opinion, that it is indifpenfably neceffary to
diftil them with the water-bath ; and as this
precaution is not ufually taken, they have
commonly an empyreumatic fmell, inftead of
that of the plant. If the virtue of thefe
waters refide only in their fpiritus rector,
feeble as it may be, it is certain, that the
ufual method of preparing them deprives

them.

RESINS. 73

them of all the properties they ought to
have.

We muft likevvife add, that the diftilled
waters of plants, prepared in pharmacy, are
not the pure fpiritus rector, in the fenfe
Boerhaave ufes the word, but that the fpi-
ritus rector is diluted with a large quan-
tity of water, which comes over in the dif-
tillation.

CHAP. XI.

Of Inflammable Reiinous Juices in general,
and of Natural Balfams in particular.

^T^HE name of refinis given to a dry, in-
■* flammable fubftance, not mifcible with
water, foluble in oils and fpirits of wine, and
which flows in a liquid ftate from the trees
that produce them. Thefe fubftances are oils,
become concrete by being dried in the air.
The difference between balfams and refins
is not well fettled. Some give the name
of balfam to fluid inflammable fubftances,
though there are likewife dry balfams. Others
call the moil odorous inflammable fubftances
by this name. Bucquet has thrown con-
fiderable light on this fubject, by confining
the name of balfams to fuch combuftible

matters

74 BALSAMS,

matters as communicate a fweet tafte to wa-
ter, and more efpecially contain odorant and
concrete acids, which may be obtained by
fublimation or deco&ion in water.

The principal fpecies of balfams may be
reduced to the three following :

i. Benzoin; this is diftinguifhed into
two fpecies, the benzoe amygdaloides, form-
ed of white tears, refembling almonds, unit-
ed by a brown matter : common benzoin is
brown, and without tears -> it emits a very
agreeable fmell, when fufed or touched with
a hot needle. The tree which affords it is
not known ; but we receive this halfam from
the kingdom of Siam, and the ifland of Su-
matra. It affords very little effential oil, or*
account of its folidity. Boiling water ex-
tracts an acid fait, in the form of needles, of
a ftrong fmell, which cryftallizes by cool-
ing. It is likewife obtained by fublimation,
and is then called flowers of benzoin. This
operation is made in two glazed earthen
pots, placed one above the other, and clofed
at the place of junction with paper. The
fublimation muft be performed with a gentle
heat, otherwife the fait will be brown.
The paper cone, formerly ufed as a fublim-
ing chimney, inftead of the upper pot, caufes
the lofs of a great part of the flowers. The
fmell of this fait is ftrong, and it produces
a cough when inhaled. Its tafte is acid; it
reddens fyrup of violets, and effervefces with

the

BALSAMS. 7|

the cretaceous alkalis. Benzoin, diftilled in
a retort, affords a very acid phlegm, a con-
crete and brown fait of the fame nature,
with a brown and thick oil. The refidual
coal contains fixed alkali.

Bergman and Scheele began the examina-
tion of the properties and elective attractions
of the acid of benzoin ; but their experi-
ments are not fufficiently numerous to afford
any very extended knowledge of this acid
and its properties.

Benzoin diflblves in fpirit of wine; and
its tincture, precipitated by water, affords
the lac virginale. The fait of Benjamin
is ufed as a good incifive remedy in pituitous
diforders of the lungs and veins. Its oil is
difcuflive, and is externally applied in para-
lytic diforders, tec.

2. Balfam of Tolu, Peru, or Carthagena.
It is imported either in cocoa nut fhells, or
in yellowifh tears, or in a fluid ftate. It
flows from the Toluifera, placed by Linnaeus
in the decandria monogynia. It may be
extracted from the fhells, by fleeping them
in boiling water, which renders it fluid. It
comes from South America, in the tract
between Carthagena and Honduras. It af-
fords the fame products as benzoin, and
more particularly the concrete acid. It is
made into a fyrup, and is ufed in diforders
of the lungs.

The acid of balfam of Tolu has not been

fuffi-

j6 RESINS.

fufficiently examined to determine whether
it effentially differs from that of benzoin.

3. Storax calamita is in tears, either red
and clean, or brown and unctuous. Its fmell
is very ftrong. It flows from the oriental
liquid amber, a plant very little known.
Newman analyzed the ftorax calamita, and
obtained a very fmall quantity of effential
oil, a concrete acid fait, and a thick oil.
This balfam is applied to the fame ufes as
benzoin, and is more particularly confumed
by perfumers. It was formerly imported
inclofed in reeds, or canes ; we now receive
it in the form of loaves, or irregular maffes,
of a reddifh brown colour, mixed with fome
tears of a lighter colour, and of a very agree-
able fmell.

CHAP. XII.

Concerning Refins.

RESINS differ from balfams in their
fmell, which is lefs agreeable, and efpe-
cially in their containing no concrete acid
fait ; the principal fpecies are the follow-
ing :

1. Balfam

RESINS. 77

i. Balfam of Mecca, of Judea, of Egypt,
of Grand Cairo. It is liquid, white, bitter,
and of a very ftrong fmell, refembling that
of lemons. It flows from a tree called
amyris opobalfamum, placed by Linnaeus
in the oclandria monogynia, and difcovered
in Arabia Felix by Mr. Forfkahl, This
liquid refin affords much effential oil, by
diflillation ; it is incorporated with fugar,
yolk of eggs, &c. and ufed as a vulnerary.

2. The balfam of copaiba, of a brown or
yellow colour, which flows from the tree
called copaiba, or copaifera, of Linnaeus,
and placed by that botanift in the decandria
monogynia. The common fort, as well as
that of the balfam of Tolu, is a mixture of
the true balfam of ^copaiba and turpentine,
according to Cartheufer. It is ufed in ulcers
of the lungs and bladder, like the foregoing.

3. Chio turpentine is afforded by the tur-
pentine tree, which bears piftachio nuts.
It is of a white, or blueifh yellow colour.
By the water-bath, it affords a very fluid ef-
fential oil ; but the oil obtained by a naked
fire is lefs fluid. The turpentine, after this
procefs, is yellower ; if the diflillation be
made with water, it is white and fllky, and
is called boiled turpentine. This is rarely
met with, and is now no longer ufed.

4. Venice turpentine is commonly ufed
in medicine, either in its natural ftate, or
combined with fixed alkali. This combi-
nation

78 RESINS.

nation is called Starkey's foap. The difpen-
fatory of Paris direcfts four ounces of effen-
tial oil of turpentine to be poured on half a
pound of nitre, fixed by tartar, before it is
become cold. The mixture is to be agitated
with a fpatula of ivory, and the veflel kept
covered with a paper, more oil being from
time to time added, till the whole forms a
white mafs. As this procefs requires feve-
ral months time to complete it, chemifts
have endeavoured to difcover more expedi-
tious methods of performing it. Rouelle,
by triturating the alkali, drop by drop with
the foap, and adding a fmall quantity of
water towards the end, prepared a conside-
rable mafs of this foap in the fpace of three
hours. M. Baume diredts one part of al-
kali of tartar, heated till it fufes, to be
ground on a levigating ftone, three or four
times its weight of effential oil of turpentine
being gradually added. When the mixture
has acquired the confiftence of a foft opiate,
he expofes it in a moift place, in a glafs veflel
covered with paper. In fifteen days, the
deliquefcent alkali forms a ftratum of liquor
at the bottom of a vefTel, the foap is in the
middle, and a portion of the oil, of a red
colour, floats above. M. Baume thinks,
that the alkali unites only with that portion
of the oil which is in the refinous ftate. M.
Le Gendre carries this notion farther, and
propofes to faturate a cold folution of fixed

alkali

RESINS. 79

alkali with oil of turpentine become thick,
or turpentine itfelf. This foap has a certain
degree of folidity, which gradually becomes
more confiderable j it affords cryftals, which
have been confidered as a combination of the
acid of the oil with the vegetable fixed al-
kali; but which, according to the acade-
micians of Dijon, confift of the vegetable
alkali, faturated with the cretaceous acid.
As this foap is very difficult to make, and
fubject to change, Macquer thinks, that
when an union of the properties of effential
oils with thofe of foap, is defired, it is more
advifable to incorporate with the white me-
dicinal foap, a few drops of that effential oil,
whofe qualities may anfwer the intended pur-
pofe. Pure volatile alkali, triturated with
turpentine, forms a faponaceous folid com-
pound, foluble in water, to which it gives
a milky appearance.

5. The refin of fir is called Strafburg tur-
pentine ; it is collected by piercing the ve-
ficules of the bark of fir trees, which grow
plentifully in the mountains of Switzerland.

6. Pitch is the juice of a kind of fir,
called abies picea ; it is extracted by inci-
fions made in the bark of the tree. It is
melted by a gentle fire, and ftrained through
facks j after which it is received in barrels.
Burgundy pitch is white, but the mixture
of coaly matter gives the black colour.
When pitch is long kept in fufion with vi-
negar,

8o RESINS.

negar, it dries, becomes brown, and forms
colophony. The dregs of pitch are burned
in a fire-place, whofe chimney leads into a
fmall chamber, terminated by a cone made
of cloth : in this lafl, the fmoke condenfes,
and forms the fine foot, called lamp-black.

7. Galipot, or refin of the pine. Holes
are bored in the lower part of this tree,
through which the refin flows into troughs.
Other incifions are made higher up, when
the former afford no more. When emitted
in the fluid ftate, it is called galipot ; the
portion which dries on the tree, in yellowiiTi
mafles, is called barras. Thefe juices are
melted, and when thickened by heat, are
filtered through draw mats, and poured into
moulds in fand. They then form maffes, call-
ed arcancon, orbray-fec. If water be added,
the matter becomes white, and forms refin,
or pitch refin. Galipot is diftilled in the large
way in the provinces of France, and affords
an oil, called huile-de-raze, or caulking pitch.
The tar, which is the empyreumatic oil
of this fubftance, is prepared with the
branches and roots of the pine. The wood
of this tree is laid in heaps, covered with
turf, and fet on fire. The oil, difengaged by
heat., not being capable of efcaping through
the turf, is precipitated into a fhallow tub,
by means of a channel, and is collected for
fale by the name of tar.

8. Tacamahaca, gum elemi, gum anima?,

arc

RESINSi 8l

aire very little ufed : the tree that affords the
fruit is not known. The gum elemi is ob-
tained from a fpecies of amiris ; the oriental
gum anime, or copal, whofe origin is un-
known, and the oxidental gum anime, or
courbaril, which flows from the hymenea,
a tree growing in South America, are ufed
to make varnifhes.

9. Maftic is in white farinaceous tears, of
a weak fmell ; it flows from the turpentine
tree, and the maflic tree. It is ufed as an
aftringent and aromatic, and enters into the
compofition of drying varnifhes,

10. Gum fandarac is in white tears, more
tranfparent than maflic. It is obtained from
the juniper, between the bark and the wood.
It is ufed to prevent the finking of ink into
paper, whofe external coating of fize has
been fcraped off in making erafures.

1 1 . The refin of guaicum, which is green-
ifh, is ufed as a remedy for the gout. It is
obtained from the guaicum tree, by inci-
fion.

12. The labdanum, or refin of a fpecies
of ciftus in Candia, is blackifh. The coun-
try people collect it by means of a ftarT, at
the end of which are fattened many leather
thongs, which they gently ftrike on the
trees. They form it into cylindrical pieces,
which are called labdanum in tortis. It is
greatly adulterated by the addition of black
fand, and is ufed as an aftringent.

Vol. IV. F 13. Dragons

82

GUM RESINS

13. Dragons blood is a red juice, ob-
tained from the draca?na draco, and feveral
other trees of the fame kind. It comes to
us in flat or round pieces, or in fmall balls,
wrapped up in leaves. It is ufed in medi-

cine as an aftringent.

CHAP

XIII,

Gum Reims.

/^UM refins are juices mixed with refin,
^* and an extractive matter, which has been
taken for a gummy fubfcance. They never
flow naturally from plants, but are extracted
by incifion, in the form of emulfive white,
yellow, or red fluids, which dry more or
lefs quickly. Water, fpirit of wine, wine,
or vinegar, diffolve them only in part. They
differ in the proportion of reiin and extract,
and their analyfis affords various refults : the
fpecies moft neceffary to be known are the
following.

1. Olibanum confifts of yellow tranfpa-
rent tears, of a very difagreeable fmell. The
tree which affords it is not known. By dif-
tillation, a fmall quantity of effential oil,
together with an acid fpirit, are obtained,
and the coaly refidue, ariiing from the ex-
tractive

GUM RESINS; 83

tractive part, is very considerable. It is ufed
in medicine for fumigations.

2. Galbanum is a fat juice, of a brown
yellow colour, and naufeous fmell. In Sy-
ria, Arabia, and at the Cape of Good Hope,
it flows from incifions made in a ferulaceous
plant, named bubon galbanum by Linnasus.
Diftilled with a naked fire, it affords a blue
effential oil, which afterwards becomes red;
and alfo an acid fpirit, with a ponderous em-
pyreumatic oil. It is a very good difcuffive
remedy, and is powerfully antifpafmodic.

3. Scammony is of a blackifri grey colour,
a ftrong and difagreeable fmell, a bitter and
very acrid tafte. The Aleppo fcammony is
diftinguifhed by its greater purity from that
of Smyrna, which is ponderous, black, and
mixed with foreign fub fiances. It is ex-
tracted from the convolvulus fcammonia of
Linnaeus. The root of this plant, cut in
pieces and preffed, affords a white juice,
which is black when dried. The different
fpecimens of fcammony contain various pro-
portions of extract and reiin, and its medical
effects differ accordingly. It is prefcribed
as a purge, in the dole of from 4 to 1 2 grains.
Mixed with a fweet extract, fuch as that of
liquorice, it forms the common diagredium;
the juice of quinces is- likewife ufed for this
purpofe. The common mode of admini-
ftering it, is after previous trituration with
fugar and fweet almonds.

F 2 4. Gum

84 GUM RESINS.

4. Gum^guttae is yellow, reddifh, with-
out fmell, and of a very acrid and corrofive
tafte. It comes from Siam, China, and the
ifland of Ceylon. It is extracted from a
large tree, not much known, called by the
natives, coddam pulli. It contains much
refin, which renders it ftrongly purgative,
in a dofe of from 4 to 6 grains. It ought
not to be internally ufed, but with the great-
eft caution.

5. Euphorbium is in yellow tears, which
have the appearance of being worm-eaten ;
it has no fmell. It flows from incilions
made in the euphorbium, which grows in

. Ethiopia, Lybia, and Mauritania. It contains
a very acrid refin, and is fo ftrongly purga-
tive, that it is reckoned among poifons. It
is not ufed, unlefs externally, in caries.

6. AfTafcetida is fometimes in yellowifh
tears, but moft commonly in loaves, formed
of a number of pieces, agglutinated together.
It has a very fetid fmell of garlic, with a
bitter and naufeous tafte. It is extracted
from the root of a fpecies of ferula, which
grows in the province of Chorafan, and
is called affafcetida by Linnaeus. The root
of this plant is flefliy and fucculent. By
expreffion, it affords a white juice, of an
abominable fmell, which the Indians ufe as
feafoning for food, under the name of food
of the gods. It is internally ufed as a power-
ful

GUM RESINS. 85

ful antifpafmodic, and is applied externally
as a difcutient remedy.

7. Aloes is a juice of a deep red, or brown,
and very bitter. It is diitinguifhed into
three fpecks ; fuccotrine aloes, hepatic aloes,
and cabaline aloes : thefe differ only in their
refpe&ive degrees of purity, the firit being
the beft. A. De JurTieu faw the preparation
of the different kinds of aloes, from the leaf
of the common aloe plant. Deep incifions
are made, from which the juice flows -, this
is decanted from its fecula, and thickened by
the fun's heat, in which ftate it is packed in
leather bags, under the denomination of fuc-
cotrine aloes. The juice obtained, by pref-
fure, from the leaves, after it is purified by
repofe, and dried, is the hepatic aloes. The
fame leaves, by ftronger preffure, afford a
portion of juice, which, mixed with the
dregs of the two foregoing, constitutes the
hepatic aloes. The firit fort contains a much
lefs quantity of refin than the two laft, which
are more ftrongly purgative. It is ufed in
medicine as a draftic purge, and is acknow-
ledged to poffefs the property of exciting the
menftrual flux in women, or the hemorrhoids
in men. It is much efteemed as a good
hydragogue.

8. Myrrh is brought to us in the form of

reddifh brilliant tears, of a Strong and rather

agreeable fmeil, bitter tafte, and exhibiting

white lines, of the form of a nail, in their

F 3 fracture.

86

GUM RESINS,

fracture. Some of thefe tears are intirely
gummy, and infipid. Myrrh comes from
Egypt, and efpecially from Arabia, in the
country of the Troglodites. The plant from
which it is extracted is not known. It con-
tains much more extract than refin. It is
ufed as an excellent ftomachic, antifpafmodic,
and cordial remedy. Cartheufer advifes lite-
rary men, whofe ftomachs are delicate, to
chew this, and fwallovv it with the faliva.
It is ufed in furgery, either in powder, or
diffolved in fpirit of wine, to cleanfe foul
ulcers, and to ftop the progrefs of caries.

9. Gum ammoniac fometimes has the form
of tears, white within, and yellow without,
and is fometimes in mafles refembling ben-
zoin. They are eaiily diftinguifhed by their
white colour and fetid fmell. It is fufpect-
ed, from the admixture of feeds it contains,
that this gum refin, which comes from
Africa, is extracted from an umbelliferous
plant. The folubility of this fubftance in
water, and in fpirit of wine, and more par-
ticularly its inflammability, are properties
in which it refembles the refinous extractive
matters of Rouelle.

Gum ammoniac is medicinally ufed as a
difcuffive remedy in obftinate obstructions ;
it is given in dofes of a few grains, in pills
or emulfions, and likewife enters into, the
compofition of many difcuffive and refolvent

platters.

10. The

GUM RESINS. 87

10. The elaftic gum, or caout-chouc, is
a vegetable fubftance, whofe nature cannot
eafily be determined; for though, in its com-
buftible property, which is applied to the pur-
pofe of illumination in America, it feems to
refemble refins, yet its elafticity, foftnefs, and
infolubility in the menftrua which diffolve
thefe laft, are characters which mew that it
greatly differs from them.

The tree which affords this fubftance
grows in feveral parts of America. Hori-
zontal inciiions are made quite through the
bark; a white and fluid juice iffues forth,
which is applied, in fucceffive coats, on
clay moulds, and dried by the fan's heat.
Various fketches of defigns are made on the
furface with an iron tool. It is then ex-
pofed to the fmoke ; and when perfectly
dried, the clay is crufhed and taken out.
The bottles, and various utenfils of elaftic
gum, which are imported into Europe, are
made in this manner.

Veffels of elaftic gum may be ufed to con-
tain water, and various fluids which do not
corrode its fubftance. If it be cut into
pieces, and the newly-cut edges applied to
each other, they adhere together with con-
fiderable force.

Elaftic gum, fet on fire, foftens, fwells
up, emits a fetid fmell, and fhrinks as it
burns.

It is not foluble in water;, and the action
F 4 of

88 GUM RESIN*.

of falinc matters on this fubftance is not
known. Macquer, who attempted to dif-
folve it in different menftrua, clearly afcer-
tained, that it was not at all acted on by
fpirit of wine, as Mefirs. De la Condaminc
and Frefneau had before aflerted, in the
Memoirs of the Academy for 1751, but
that oils diflblve it, by the affiftance of
heat. Neverthelefs, as his intention was to
liquefy, or diflblve it in fuch a manner, as
that it might be ufed, and refume all its
properties, by the evaporation of the folvent,
it became neceflary for him to ufe a more
volatile menftruum than oils, which remain
combined with the gum, and deprive it of
its elafticity. Highly rectified ether, which
readily diflblves this fubftance, and may be
quickly evaporated, anfwers the purpofe per-
fectly well. (See the Memoirs of the Aca-
demy for the year 1768.) And though this
fluid is very expenfive, he thinks it may be
advantageoufly ufed in making certain uten-
fils, fuch as catheters, by fucceflively ap-
plying this folution on a mould of wax, till
it is of the required thicknefs. When it is
dry, the wax may be eafily feparated, by
immerfion in boiling water. The foftnefs
and elafticity of this inftrument, renders it
extremely ufcful for fuch as are under the
neceftity of continually ufing it.

Such was the ftate of our knowledge, re-
fpecting the elaftic gum, when, in the month

of

GUM RESINS, 89

of April, 178 1, Mr. Berniard, well known by
the accuracy of his experiments, inferted, in
the Journal de Phyfique, an excellent memoir
concerning this Angular fubftance. This
chemift concluded, from his experiments,
that the elaflic gum is a peculiar kind of
fat oil, coloured by matter which is foluble
in fpirit of wine, and blackened by the
fmoke, to which each coating is expofed to
dry. Water does not at all change it; fpirit
of wine deprives it of its colour, by boil-
ing. The cauftic fixed alkali does not act
upon it. Oil of vitriol reduces it to the
ftate of coal, itfelf becoming black, and af-
fuming the fmell and volatility of the ful-
phureous acid. The common nitrous acid
2cts in the fame manner on this fubftance as
on cork, changing its colour to a yellow*
Spirit of nitre very quickly deftroys it, but
the muriatic acid does not affect it in the
leaf!:. Rectified vitriolic ether did not dif-
folve it. This fact, as the author obferves,
muft appear lingular, to all who are ac-
quainted with the exact nefs and the veracity
of Macquer. Nitrous ether diffolves it, and
becomes yellow, affording, by evaporation,
a tranfparent friable fubftance, which is fo-
luble in fpirit of wine, and is in fact a true
refin, formed, according to the author, by
the action of the nitrous acid on the elaftic
gum. The effential oil of lavender, and
likewife thofe of afpic and of turnfole, dif-

folved

go GUM RESINS.

folved it by the help of a flight heat ; but
they formed gluey fluids, which daubed the
hands, and confequently were not applicable
to any ufe. Afolution of elaftic gum, mix-
ed with fpirit of wine, depofited white
flocks, infoluble in hot water, at the top of
which they floated, and became white and
folid, like wax, by cooling : it appeared to
be a true concrefcibie fit oil. Oil of cam-
phor diflblved elafiic gum, by Ample mace-
ration. By evaporating this foiution, the
camphor was driven oft, and an amber-
coloured matter, of a firm confidence, fcarce-
ly adheiive, remained in the capfule, and
was found to be eafily foluble in fpirit of
wine. Fat oils, bo i led on elaftic gum, dif-
folve it, as does like wife wax. This Jub-
ilance does not melt by the heat of boiling
water; but when expofed to a greater heat,
in a filver fpoon, it is converted into a black
thick oil, emits white vapours, and remains
fat and adheiive, though expofed to the air
for feveral months, and does not recover the
drynefs and elasticity in which its chief uti-
lity confifts. Laftly, Mr. Berniard con-
cluded his inquiries, by analyfing elaftic gum
with a naked fire. One ounce afforded a
very fmall quantity of phlegm ; an oil, at
firft light and clear, but afterwards thick ;
and coloured and volatile alkali, in a quan-
tity which he has not afcertained. The
coaly refidue was fimilar to that of refins*

and

GUM RESINS. 91

and weighed 12 grains. This chemift attri-
butes the volatile alkali to the foot with
which the elaftic gum is coloured.

We muft obferve, that this analyfis does
not accurately afcertain the nature of elaftic
gum, becaufe the action of acids on this
fubflance does not refemble that which they
exhibit with fat oils, and which is much
more rapid ; becaufe cauftic alkalis do not
convert it into foap ; becaufe it does not
melt, but by a degree of heat much greater
than is neceffary to melt the moft folid fat
oils ; becaufe no fat oil becomes dry and
elaftic, &c. &c. The author, befides, in
his fifteenth experiment, affirms, that this
gum is compofed of two diftinct fubftances,
which he does not exhibit; and he con-
cludes, by confid;ring it as the product of
art. From all thefe reflections, and many
others which may be added, concerning the
experiments of Mr. Berniard, valuable as
they are, we think, with him, that much
remains to be done, to afcertain the proper-
ties of this fubftance, and to enable us to
decide refpedting its nature.

CHAP.

gZ FECULA

CHAP. XIV.

Of the Pure Fecula of Vegetables.

/HpHE juices of vegetables, elaborated iu
■* their veffels, become thick, and are
gradually depoiited on the furface of the
fibres, which are by that means fupported
and augmented, or become accumulated, in
a more or lefs folid form, in the organs of
the plant. After having treated of the fluid
parts of thefe organized fubftances, it is ne-
ceflary to examine the fubftance of which
their folids are compofed. We are far from
pofTeffing an accurate knowledge of all the
folid fubftances contained in vegetables; but
it appears, that when treated by the pro-
ceffes we are about to defcribe, they are re-
ducible into a dry, pulverulent, inlipid,
white, grey, or varioufly coloured fubftance,
infoluble in cold water, and of an earthy
appearance, called fecula.

To obtain this fubftance, a root, item,
leaf, or feed, is reduced to a pulp, by pound-
ing. Succulent vegetables may be treated
in this manner, without the addition of wa-
ter ; but in general water is added, to faci-
litate the feparation of the fibres, and to

carry

FECULA. 9J

carry off the divided and pulverized parts.
The pulpy matter, by ftrong preflure, af-
fords a turbid, white, or coloured fluid,
which after fome time depofits, by flanding,
a fubilance partly fibrous, and fometimes
pulverulent, which is the true fecula of ve-
getables. Some parts of vegetables appear
to be intirely compofed of this matter ; fuch
as the feeds of gramineous and leguminous
vegetables, tuberous roots, &c. Thefe parts
in general afford the fineft and mofl abun-
dant fecula. As to the tender items and
leaves of vegetables, their more fibrous tex-
ture affords only a coarfe-coloured filament-
ous depofition, diftinguifhed by the name of
coarfe fecula. If thefe be well dried, pul-
verized and warned, the w7ater carries off a
much finer fecula, perfectly fimilar to that
of the tuberous roots and gramineous feeds.
The chemift, therefore, makes no other dif-
tinclion between thefe two kinds of fecula,
than that the firft is obtained from a lefs
fibrous part, confifting, as it were, of cells,
in which nature has depofited dry or fari-
naceous mucilage; while the fecond, being
of a more fibrous texture, requires its or-
ganization to be deftroyed by a more arti-
ficial procefs.

All the vegetable parts of folids, ftricUy
fpeaking, afford a kind of fecula; but we
fliall here more particularly fpeak of fuch as
are prepared by art for food or medicine.

The

94 FECULA.

The fecula of bryony, potatoe, caflava, fagoj
falop, and ftarch, are thofe we (hall par-
ticularly attend to.

i . To prepare the fecula of bryony, the
firft roots are deprived of their bark, rafped
in pieces, and fubmitted to the prefs. The
juice is white, and depcfits a very fine fe-
cula, from which, at the end of twenty-
four hours, the liquid is decanted, and it is
dried. As this fecula contains a certain
quantity of extract, left by the juice, it is
very acrid, and purges violently : by waffl-
ing, it becomes finer, and whiter, but at the
fame time lofes its purgative virtue. This
method of preparing the fecula of bryony
affords but a very fmail quantity, but a
much greater may be obtained, by moiften-
ing, with water, the mafs remaining in the
prefs, (training this water through a hair
lieve, to feparate the groffer fibres, and leaving
it at reft, and to depoiit its fecula, at which
time the water is to be decanted off, and the
powder dried. This laft fecula is not pur-
gative, like the former, becaufe it has been
deprived of its extractive matter by the wa-
ter. Mr. Baume has obferved, that the fe-
cula of bryony is abiolutely the fame as
ftarch, and may be made into hair powder,
to the great faving of corn. The fecula of
the roots of arum, and cornflag, are pre-
pared in the fame way for medical ufes.

2. Potatoes are among the moil: ufeful

alimentary

FECULA. 95

alimentary fubftances, with refpect to their
abundance and fertility. They afford a large
quantity of very fine white fecula, which,
when boiled, is an excellent food. It is ob-
tained by fcraping the potatoes into a iieve,
and pouring thereon a large quantity of wa-
ter. The fluid carries off the fined: and mofl
divided part of the fecula, which fubiides
by Handing. The water is decanted off, and
the fecula, dried by a gentle heat, has the
form of a very fine white powder. Mill",
confifting of a kind of rafps, turning on cy-
linders, have besn contrived, and are ufed
to great advantage in preparing this fecula.

3, The Americans extract, from the root of
a very acrid plant, called manioc, a mild nou-
rifhing fecula, which they call caffava. They
ftrip the root, rafp it, and put it into a fack
of rufhes, made in the form of a cone, and
of a very open texture, which they fufpend
to a ftaff, placed acrofs two upright pofts.
At the lower extremity of this fack, they
hang a heavy veffel, which by its weight
preffes the root, and receives the juice which
flows out, and is a moft acrid and dangerous
poifon. When the fecula is well preffed,
and deprived of all its juice, it is dried in
the fmoke, fifted, and then forms caffava.
This farina is fpread on a hot plate of iron,
and turned till both its furfaces acquire a
reddifh yellow colour, which denotes that
it is fufficiently baked. In this ftate it is

called

96 FECULA.

called caflava bread. When the farina is
heated in a veffel, and agitated from time to
time, it takes the form of grains, called
couac. A very fine and mild fecula, called
mouffache, falls to the bottom of the ex-
prefled juice, and is ufed for paftry.

4. Sago is a dry fecula, reduced into
grains by the a&ion of fire, and comes to
us from the iflands of Molucca, Java, and
the Phillipines. It is obtained from a kind
of palm, called landan, in the Moluccas.
The trunk of this tree contains a fweetpith,
which the inhabitants take out after having
fplit the wood ; they then bruife it, and put
it into a kind of cone, or funnel, made of
bark, and pour on a large quantity of water.
This fluid carries with it, through the fieve,
the fineft and whiteft part of the pith, the
fibrous part remaining behind. The water
is received into pots, and gradually depofits
the fecula. The clear water is then decant-
ed, and the depofited matter is paffed through
perforated plates, which give it the form of
fmall grains. The red colour on their fur-
face rifes from the action of fire, ufed in the
drying. Thefe grains, or fago, become foft
and tranfparent in boiling water, and form,
with milk or foup, a light and agreeable li-
quid, which is ftrongly recommended in
phtjiifical diforders.

5. Salep, falop, falab, &c. is the root of
a fpecies of orchis, prepared by the orien-
tals.

FARINA. 97

tats. They felecT: the fineft bulbs of this
plant, which they peel, and boil, after pre-
vioufly foaking them in cold water. They are
then ftrung, and dried in the air. M. Jean
Moult defcribes another procefs for prepar-
ing falop, which may be ufed with every
kind of orchis. The roots, either dry or
under water, are rubbed with a brum, to
take off the external pellicle; after which,
by drying in an oven, they become very hard
and tranfparent. Thefe are very eafily re-
duced into powder, which, with hot water,
forms a nourifhing jelly, much praifed by
Geoffroy, in all diforders arifing from an '
acrid ftate of the lymph, and efpecially in.
confumptions, and the bilious dyfentery.

CHAP. XV.

Concerning the Farina, and Starch of Corn.

GTARCH, properly fpeaking, is a fecula
^ abfolutely fimilar to the foregoing ; but
as the farina of corn, of which it is a con-
ftituent part, is one of the mofl important
fubltances that come under the examination
of the chemift, we fhall treat more fully on
this than on the other fecula.

The fubftance called flour, is in general
Vol, IV. G dry,

98 FARINA.

dry, friable, infipid, capable of acquiring
tafte and digeftibility, by the action of fire,
and compofed of feveral fubftances eafily fe-
parable from each other. It exifts in the
feeds of gramineous plants, more efpecially
wheat, rye, barley, oats, rice, buckwheat,
&c. Leguminous plants likewife appear to
contain a compound analogous to flour; but
the flour of wheat only can be faid truly to
poflefs the requilite properties, becaufe it is
the only farina in which the different fub-
ftances are duly proportioned to each other.
Though the economical ufe of the flour of
wheat, as the principal article of nourifhment,
has been eitablimed from time immemorial, it
is but lately that chemifts have began to ex-
amine it. Meffrs. Beccarri, an Italian phy-
lician, and Keffel Meyer, in Germany, are
the firft chemifts who endeavoured to fepa-
rate the different fubftances contained in
flour, Meffrs. Rouelle, Spielman, Malouin,
Parmentier, Poulletier de la Salle, and Mac-
quer, continued and carried the experiments
of thefe philofophers much farther. Mr.
Parmentier, efpecially, has profecuted this
inquiry with uncommon zeal and activity.
His refearches into the nature of alimentary
fubftances, the component parts of flour,
the different fpecies of fecula, and on all
nutrative vegetables in general, are, without
doubt, the moft complete and exact of any
that have been made in this way.

Water

VEGETABLE GLUTEN. 99

Water is an agent of the greateft utility,
and leaft capable of altering the feveral mat-
ters it takes up, or feparates, in the order of
their folubility. This fluid is ufed, with
the greateft fuccefs, to obtain the different
fubftances of which wheat flour is compofed.
To perform this true analyfis, a pafte is made
with flour and water, and kneaded in a veflel
of water, underneath a ftream from a cock ;
the water carries off a very fine white pow-
der, and the kneading muft be continued till
this fluid paffes oft clear. The flour is then
found to be feparated into three fubftances;
a greyifh and elaftic matter remaining in
the hand, which has been called the gluti-
nous, or vegeto-animal part, on account of
its properties ; a white powder, depofited by
the water, which is the fecula, or ftarch ;
and a fubftance, held in folution by the wa-
ter, which appears to be a kind of mucila-
ginous extract. We (hall examine the pro-
perties of each of thefe three fubftances in
order.

§ I. Concerning the Glutinous Part of
Wheat.

The glutinous part, is a tenacious, ductile,
elaftic matter, of a whitifh grey colour.
When drawn out, it extends about twenty
times its length before it breaks, and appears
as if compofed of fibres, or filaments, placed

G 2 befide

813

IOO>-*^VEGETABLE GLUTEN.

according to the direction
1 wmcn it has been drawn. If the force
ceafes, it refumes its original form by its
elafticity. By drawing it out, in different
directions, it may be made fo thin, that its po-
lifhed furface refembles the texture of animal
membranes. In this ftate it adheres ftrongly
to dry bodies, and forms a very tenacious
glue, which was ufed by fome perfons to join
broken china, long before chemifts found
the means of obtaining it in large quantities.
Mr.Beccari has obferved, that the proportion
of glutinous matter is from a fifth, to a third,
and more, in flour of the beft quality -y he
has likewife. obferved, that this quantity va-
ries in different feafons, and according to
the nature of the corn.

The fmell of the glutinous matter is faint,
and refembles that of mucilage ; expofed to
a fire capable of fuddenly drying it, it fwells
up prodigioufly. In a dry air, or mild heat,
it dries very well. It is then femi-tranfpa-
rent, and hard, like glue, and fnaps fhort
like that fubftance.

If in this ftate it be placed on burning
coals, or applied to the flame of a candle, it
exhibits all the characters of an animal fub-
ftance; it decrepitates, fwells, liquifies, curls
up, and burns like a feather, or a piece of
horn, emitting, at the fame time, a ftrong
and fetid fmell. By diftillation, it affords,
like animal fubftances, alkaline fpirit, con-
crete

VEGETABLE GLUTEN. 101

crete volatile alkali, or ammoniacal chalk,
and an empyreumatic oil. Its coal is very
difficultly incinerated, and does not contain
fixed alkali.

Frefh gluten, expofed to a hot and dry
air, becomes changed, and putrifies abfo-
lutely in the fame manner as animal fub-
ftances. When it retains a fmall quantity
of ftarch, this laft pairing to the acid fer-
mentation retards and modifies the putrid
fermentation, and converts the fubftance in-
to a ftate nearly flmilar to that of cheefe.
Rouelle the younger prepared a cheefe with
the gluten, which Angularly refembled in
its fmell and tafte, that of Gruyeres, or of
Holland.

Water does not at all diflblve this glutinous
matter. By boiling in this fluid it becomes
folid, lofes its extensibility and adhefive quali-
ty, but does not acquire either tafte or folubi-
lity in thefaliva. Neverthelefs, we rauft ob-
ferve, that the gluten owes its elasticity and
folidity to the water which formed the pafte.
In fad:, this vegeto-animal portion, though
capable of becoming folid and elaftic, is
pulverulent, and without cohefion in the
flour ; but as foon as water is added, its
particles abforb the fluid, and adhere toge-
ther, forming the elaftic fubftance called
gluten. Water, therefore, contributes greatly
to the formation of this fubftance, and it
G 3 may

102 VEGETABLE GLUTEN.

may perhaps be confidered as a compound,
faturated with, and incapable of absorbing
a larger quantity of water. This is fo true,
that it abfolutely lofes its adhefion and elas-
tic properties by drying.

Moft faline fubftances act more or lefs
efficacioufly on the gluten. The cauftic
fixed alkalis in the fluid ftate diiTolve it by
boiling. This folution is turbid, and de-
pofits, by the addition of acids, a gluten
which is not elaftic.

The mineral acids diflblve the gluten.
The nitrous acid diffolves it with great ac-
tivity, and Mr. Berthollet has obferved,
that this acid difengages mephitis, as it does
from animal fubftances. When this elaftic
fluid has been emitted, the folution affords
a large quantity of nitrous gas, and becomes
of a yellow colour. By evaporation it af-
fords cryftals of the acid of fugar. The vi-
triolic and marine acids form brown or vio-
let folutions of this fubftance, from which
a kind of oily matter feparates ; the gluten
being truly decompofed. Mr. Poulletier,
who has made many experiments on this
fubftance, has difcovered, that ammoniacal
falts may be obtained from thefe combina-
tions, diftblved in water, or fpirit of wine,
and evaporated in the open air.

From thefe fadts, it follows, that this
fubftance is totally different from all thofe
hitherto known in vegetables, and that in

many

STARCH.

°3

many of its characters it refembles the fi-
brous part of the blood. It is to this gluten
that wheat flour owes its property of form-
ing a very adhefive parte with water, and
the facility with which it rifes in leaven.
The gluten does not appear to exift, at lead
in any confiderable quantity, in other farina,
fuch as that of rye, barley, buckwheat,
rice, Sec. ; all which form folid, opake
partes, fcarcely ductile, eafily broken, and
which do not ferment when expofed to the
temperature by which that procefs is ef-
fected in wheat parte. The prefence of the
gluten appears therefore to be neceflary for
the produdion of good bread.

Mr. Berthollet thinks that this glutinous
fubftance contains phofphoric fait, like ani-
mal matters, and that this is the caufe of
the difficulty with which its charcoal is
incinerated. Rouelle the younger found
a glutinous fubftance analogous to that of
wheat in the green fecula of plants, which
afford volatile alkalis and empyreumatic oil,
as does the vegeto-animal fubftance here
treated of.

§ II, Concerning the Starch of Wheat.

Starch, or the amylaceous fecula, com-

pofes the greater part of flour ; it is the

white fubftance which fubiides from the

water ufed in obtaining the pure gluten.

G 4 This

104 STARCH,

This fubftance is very fine, and foft to the
touch ; its tafte is fcarcely fenfible. Its
colour is of a grey and dirty white, when
extracted by the procefs we have defcribed;
but the ftarch-makers render it extremely
white by fuffering it to remain in the water
for a time, after it has become acid. It
appears from the experiment of Mr. Poulle-
tier, that the fermentation which takes place
in this fluid, whitens and purifies the ftarch
by attenuating, and even deftroying the ex-
tractive mucilaginous fubftance with which
it is vitiated at firft. Starch, chemically
confidered, is a mucilage of a peculiar na-
ture. This mucilage, which has been im-
properly confidered as an earth by fome
chemifts, differs greatly from the glutinous
part. It burns without emitting an empy-
reumatic fmell. By diftillation with a naked
fire, it affords an acid phlegm, of a brown
colour, and a very thick empyreumatic oil
towards the end. Its coal is eafily reduced
to afhes, which contain fixed alkali.

Starch is not foluble in cold water, but
when boiled in water, it forms a kind of
glue, that, when expofed to a moift air,
gradually lofes its confiftence, ferments, be-
comes four, and at laft mouldy.

The nitrous acid produces the acid of
fugar with this fecula, which is perfectly
fimilar to thofe we have treated of in the
foregoing chapter.

A3

SACCHARINE MUCILAGE. 10$

As ftarch forms the greateft part of flour,
it cannot be doubted, but that it is the
principal alimentary fubflance contained in
flour, and in bread.

§ III. Concerning the Mucilaginous Ex-
tractive Part of Flour.

By evaporating the pure water with which
the pafte was wailied, and from which ftarch
had been depofited, Mr. Poulletier obtained
a vifcous gluey fubftance of a brown yellow
colour, and Jdightly faccharine tafte. This
fubftance, denominated by its difcoverer the
mucofo-faccharine matter, exhibited all the
phenomena of fugar in its combuftion and
diftillation. It is this which excites the
acid fermentation in the water that floats
above the ftarch ; for, as Macquer well ob-
ferves, the latter is not at all foluble in cold
water.

The mucofo-faccharine matter exifts in a
very fmall proportion in wheat corn, but
may pethaps be more abundant in other
kinds of flour.

It cannot be doubted, notwithstanding the
fmall quantity of this fubftance contained
in wheat corn, but that it is principally
concerned in the fermentation by which
pafte is leavened. This inteftine motion, fo
neceffary in the making of good bread, is not
yet well underftood. It may perhaps con-

fift

106 COLOURING MATTERS.

lift in the commencement of fermentation,
which is putrid in the gluten, acid in the
ftarch, and perhaps fpiritous in the mucofo-
faccharine matter; and rrom thefe three inci-
pient fermentations mutually impeding each
other, the lighter compound, which by bak-
ing forms bread, may probably arife. At all
events, it is certain, that the three fubftan-
ces we fpeak of are fo combined and altered
in bread, that they can no longer be fepa-
rated. The adtion of heat is fufficient,
without fermentation, to produce this inti-
mate combination -y for unleavened bread,
according to Malouin and Poulletier, does
not afford the glutinous matter.

From the foregoing fadts we fee, how
greatly other kinds of flour differ from
that of wheat, and ftill more thofe legumi-
nous and farinaceous feeds, fuch as beans,
peafe, chefnuts, &c. are far from poffeffing
the qualities neceflary to make good bread.

CHAP. XVI.

Concerning Vegetable Colouring Matters,
and their Application to the Art of Dying.

T 7Egetables contain colouring matters in
* all their organs. Thefe parts differ great-
ly from each other; for a vegetable fubftance,

which

COLOURING MATTERS, IOJ

which has no apparent colour, often affumes
a very evident tinge, by peculiar menftruums.
The art of dying, all the proceffes of which
are abfolutely chemical, is founded on the
folubility of colouring matters in different
menflrua, the method of applying them to
fubftances propofed to be dyed, and of ren-
dering them fixed. In treating of the pro-
perties of each colouring matter, we mail
have occafion to fpeak of the principles of
this important art, which is excellently
treated of in the works of Hellot, Macquer,
Le Pileur d'Apligny, Hecquet d'Orval, and
the Abbe Mazeas.

The colouring matter of vegetables pro-
perly fo called, is not yet well known. Rou-
ellefuppofed that the colouring matter, which
is fo abundant in the vegetable kingdom, was
analogous to the gluten of flour; but it is
certain, that this matter prefents different
chemical characters, according to the bafe
with which it is united. When, therefore,
it is faid, that a colour is extractive, refinous,
&c. the terms apply rather to the bafe, than
to the colouring matter. The true colour-
ing matter of vegetables ufed in the arts,
is doubtlefs of a very fubtle nature, and is
perhaps as divifible as the principle of fmell.
It may even be fuppofed, that it confifts
only in a peculiar modification of the folid
and liquid parts of vegetables. It is necef-
fary to repeat in this place, that the colour

of

108 COLOURING MATTERS.

of vegetables is for the moft part produced
by the contad: of light; but the manner in
which light produces this efFed:, is a pro-
blem not yet folved. However this may
be, as it is impoffible to feparate the colour-
ing m?tter intirely from the vegetable bafe
it adheres to, thefe two fubftances are ufually
taken together for the colouring matter.

No chemift has more accurately diftin-
guimed the vegetable colouring matters,
considered with refpeft to the art of dying,
than Macquer ; and his theory concerning
the applying and fixing thefe colours to
fubftances intended to be dyed, muft be ad-
mitted as highly fatisfadory. As it is our
intention to conned: this theory of dying
with the hiftory of the chemical properties
of vegetable colouring matters, we mall
conlider them in the fame point of view.

i. A great number of vegetable colouring
matters, which are of an extractive or Sapo-
naceous nature, are readily diifolved in wa-
ter. Baftard rocket, madder, logwood,
redwood, and Brafil wood, afford yellow or
red colours of this kind. It may be eaiily
conceived that fubftances tinged with thefe
matters, readily give out their colour to
water ; and it is therefore found neceftary,
in order to render them durable, to make ufe
of fome additional fubftance capable of de-
compofing and fixing them ; as for example,
crude tartar, alum, and other falts. Thefe

falts

COLOURING MATTERS, I09

falts are called corrofives. A difengaged
acid would produce the fame effe&s, but it
would alter the colouring matter. The
portion of fupcrabundant acid of the alum
unites with the alkali of the colouring fapo-
naceous extract, and caufes the relinous part,
which is then infoluble in water, to be pre-
cipitated on the fubftance intended to be
dyed. However, this colouring portion, ren-
dered infoluble by the alum, or the corro-
five, is of two kinds ; the firft is very folid,
and refifts the air, foaps, and all the liquors
which dyers call proofs. This kind of co-
lour is called a good or ftrong dye. The
other is changed by the air, and efpecially by
the adtion of the proof liquors : It is called
a falfe dye. To difcover the nature of thefe
colours, and the duration of dyes in general,
Mr. Berthollet propofes the ufe of the de-
phlogifticated or aerated muriatic acid, which
in a very fhort time, by its excefs of the
oxyginous principle, produces the fame ef-
fect as the pure air of the atmofphere would
effed: in a much longer fpace of time. The
quantity of acid required to difcolour and
intirely bleach any dyed fluff, as well as the
time required for this purpofe, may ferve to
determine the folidity and duration of co-
lours.

It is obfervable that wool takes the dye
better than any other fubftance; and that filk,
cotton, and flax, in the order we have men-
tioned

110 COLOURING MATTERS.

tioned them, are dyed with more difficulty,
and retain the colouring fubftance more
weakly.

Writers on the art of dying, hold differ-
ent opinions refpedting the manner in which
the colouring parts apply themfelves to the
fubftances expofed to their contact. Many
have fuppofed that this application takes
place only in proportion to the number and
magnitude of the pores in the various fub-
ftances ; and that wool takes the dye better
than filk or thread, becaufe its pores are
more open and numerous. But Macquer
thinks, that the greater or lefs facility with
which the colour is applied, depends on
the refpective nature of the colouring parts
and the fubftance propofed to be dyed ; and
that the art of dying is truly an external
tinge or painting, which fucceeds and lafts
by virtue of an affinity and intimate union
between the colour and the dyed fubftance.
This celebrated chemift adopted the opinion
here recited, in confequence of the nume-
rous experiments for which this art is greatly
indebted to him.

2. Another kind of colouring matter feems
to be compofed of faponaceous extract and
refin. Macquer calls them refino-terreftrial
matters. When thefe matters are boiled in
water, the reiinous fubftance they contain
melts, and is difperfed in the fluid by the af-
fiftance of heat, and by virtue of the diffolved
faponaceous portion ; but it precipitates in

oro-

COLOURING MATTERS. Ill

proportion as the decoction or bath becomes
cold. Confequently, when wool, or any-
other fubftance is plunged in a decoction of
this nature, the relin feparates by cooling,
and applies itfelf without any other prepa-
ration •, and as it is not foluble in water, it
forms a lafting dye. Colouring matters of
this clafs are obtained from almoft all aftrin-
gent vegetables, fuch as the hufks of nuts,
roots of walnut-tree ; or of dock, fumach,
bark of alder, fandal-wood, &c. Thefe co-
lours are all yellow, and are called root
colours by the dyers. They generally ferve
to form a very good ground, on which other
more brilliant colours may be applied. It
may be obferved, that colouring ingredients,
which require no preparation either in the
bath, or in the ftuff to be dyed, are more
eafily applied to ufe than others.

3. The colouring principle of many other
fubftances refides in a purely refinous mat-
ter, infoluble in water, and fome not even
in fpirit of wine ; but they all are foluble
in alkalis, which convert them into a kind
of foaps, foluble in water. The principal
colours of this nature employed in dying
are the following :

A. The annatto, a kind of fecula, ob-
tained by maceration of the feeds of the
urucu putrefied in water. This fecula de-
pofited during the putrefaction, is firft red,
and in procefs of time becomes of a brick

duft

112

COLOURING MATTERS.

duft colour. The parte is mixed in water
with the cendres gravelees, fliortly to be
defcribed, and forms a bath, wherein the
fluffs intended to be dyed are plunged. A
gold, or orange yellow colour, of coniidera-
ble beauty, is depoiited without the affifl-
ance of a corrofive.

B. The flower of carthamus, or baftard
faffron, affords a very fine red colour, by
"It contains two diftincl
the one purely extractive

the fame procefs,
colouring parts

and foluble in water, the other refinous.
In order to obtain the latterL the foluble
part of the carthamus muft firft be carefully
warned away. The remainder is mixed with
the cendres gravelees, or fait of foda; and the
mixture being lixiviated, forms a bath. But
as the alkali alters the colour, and renders it
dull, the dyed fluff is plunged in water
rendered acid by lemon juice : the acid
feizes the alkali, and leaves the colouring
matter, which it enlivens, and caufes to be-
come red. A coloured fecula is obtained
by a iimilar procefs, which, mixed with
brianfon chalk in powder, compofes the
rouge ufed by the ladies.

C. Archil is a pafte prepared with moffes
and lichen macerated in urine with lime :
The latter dilengages the volatile alkali,
which developes the red colcur. Archil
mixed with water, affords a dye without
any other preparation j with alkalis, it flrikes

a violet

COLOURING MATTERS. 1 13

a violet colour ; but this is a falfe dye, which
changes in the air, and becomes yellow by
the action of acids.

D. Indigo, which is of a deep violet blue,
of a coppery tinge, is a fecula prepared at
St. Domingo, and in the Antilles, &c. by
macerating the flalks of the anillo, or indigo
plant, in ftone troughs, with water. The
water becomes blue, and after flrong agi-
tation the fecula precipitates. The indigo
feparated from the water, is put into cloths
to drain, and after being dried in fmall wooden
boxes, it is broken into pieces. It is efteemed
good when it floats on water, and burns intirely
away on a red-hot fhovel. The colouring
matter is extracted by alkalis, and applied,
without any other preparation, to the .fluffs.
It cannot be brightened by acids, becaufe
they change its colour.

4. Certain colouring fubftances are foluble
in oils. Alkanet, or the red- root of a kind
of buglofs, communicates its colour to oil.
Spirit of wine likewife diffolves feveral co-
louring matters : green feculae diffolve in
this menflruum, as well as in oil. It may
eafily be conceived, that thefe colours, are
not ufed in dying, becaufe the liquids ne-
ceffary to extract them cannot be employed.

Such are the principal circumftances in
which our knowledge of vegetable colours
confifts. Every immediate principle of ve-
getables may constitute the bafe of thefe co-

Vol> IV. H louring

114 DESTRUCTIVE DISTILLATION

louring parts, fince they are found of fapo-
naceous, reiinous, and extractive kinds.
Some even appear to be of the nature of fat
oils, being infoluble in water, or ardent
fpirit, though they readily combine with al-
kalis. Laftly, there are fome which are
analagous to the glutinous part, according
to Rouelle.

There is every reafon to think, that fu-
ture inquiries, if ikilfully made, will dis-
cover many other properties of thefe fub-
flances, which greatly abound in vegetables,
and that they will contribute to the im-
provement of the art of dying; an art to
which chemiftry is well adapted to render
the moft important fervices.

CHAP. XVII.

Concerning the Analyfis of Plants, by de-
ftrudtive Diftillation, or a naked Fire.

AFTER having examined all the fub-
ftances which may be obtained from
plants, by fimple methods, which are in-
capable of changing them; and after having
confidered thefe matters as the immediate
principles of organized fubflances, it is ne-

cefTary

OF PLANTS. II5

ceflary to attend to the alterations they fuf-
fer when expofed to heat.

The ancient chemifts were acquainted
with no other method of analyfing vege-
tables, and all their refearches into the na-
ture of thefe bodies, confifted in determin-
ing how much fpirit, oil, and volatile fait
they afforded by diftillation. This method
is at prefent no longer efteemed, as it is
known, that moft plants afford nearly the
fame products; and the diftillation of a great
number of different vegetables, made by che-
mifts, in other refpects deferving the efteem
of the public, has only ferved to undeceive
us. In fact, how can it be imagined, that
the action of fire, exerted on all the different
principles in a vegetable fubftance, fuch as
extract, mucilage, oil, refin, fait, gluten,
&c. which decompofes each of thefe prin-
ciples in a peculiar manner, can afford
any knowledge refpecting their nature and
quantity ; more efpecially when it is ob-
ferved, that the products of thefe feveral
decompofitions unite together, and produce
new fubftances, fuch as did not exift in the
vegetable under examination ? The analyfis
of vegetables, by diffyllation, is therefore
complex and fallacious.

However, as none of the methods which

art is in poffeflion of, ought to be neglected,

in the chemical examination of any fubftance,

we mav have occafional recourfe to this ana-

H 1 lyfis,

Il6 DESTRUCTIVE DISTILLATION

lyfis, always carefully obferving, that it is not
too much to be depended on. It ibmetimes
happens, that when the effects of aqueous,
fpiritous, and oily menftrua, on any fub-
ftance, are compared with the alterations
produced in it by fire, thefe laft confirm the
deductions made from the action of the fol-
vents, and by the products of the diftilla-
tion, indicate the fubftances contained in
greater or lefs quantities, the nature of its
falts, &c. But to make valuable deductions
from the analyfis by fire, it is neceffary, i .
To be well acquainted with the action of
fire, on each immediate or proximate prin-
ciple, fuch as extract, mucilage, faline mat-
ter, oily juices, the fluid, or folid part, &c.
2. To compare the products, afforded by
diftillation, of the whole vegetable, with
thofe ufually afforded by the proximate prin-
ciples, treated in the fame manner. 3. To
analyze the vegetable by menftruums, in
order to obtain its proximate principles,
and to make ufeful inductions from the al-
terations it has fuftained by fire.

The procefs of diftilling vegetables by a
naked fire, is very eafy and fimple. A given
quantity, of a dry vegetable, is put into a
glafs, or earthen retort, fo as to fill it not
more than half or two thirds ; the retort is
then placed in a reverbaratory furnace, and
a receiver of a proper fize adapted. It was
formerly fuppofed nsceffary to ufe a receiver,

perforated

OF PLANTS. 117

perforated with a fmall hole, to give vent
to the air faid to be difengaged from ve-
getables, and tending to burft the veflels.
But it is at prefent known, that the aeri-
form fluid, which efcapes from thefe bodies
during diftillation, is fcarcely ever air, but
confifts of cretaceous acid and inflammable
gas. Now, as thefe elaftic fluids are pro-
ducts of the vegetable compound, by fire, as
well as the phlegm, the oils, and the vola-
tile falts, it is equally neceflary to collect
them. For this purpofe, a perforated re-
ceiver, communicating with an inverted glafs
veflel, filled with water or mercury, may be
ufed. By this means, the liquid products
are collected in the receiver, and the aeri-
form products under glafs veffels, placed on
the fhelf of a pneumato-chemical apparatus.
When the fubftance diftilled affords a con-
crete fait, an adapter, or long glafs veifel, is
fixed between the retort and the receiver, in
order that the fublimation may be made on
its internal furface. The operation is be-
gun, by placing a few pieces of lighted char-
coal beneath the retort, and the fire is gra-
dually increafed till the veffel is red-hot, and
nothing more comes over. After the whole
has become cold, the apparatus is unluted,
to examine each of the products obtained.

Though the diftillation of vegetables never
affords products which may be confidered
as principles of the plant, yet thefe products

H 3 differ

1 1 8 PRODUCTS FROM PLANTS

differ confiderably from each other, and re*
quire to be carefully diftinguifhed.

The firft product which comes over, is an
aqueous liquor, containing certain odorous
and faline principles. As the diftillation ad^
vances, the colour and faline properties of
this phlegm become ftronger. It is fuc-
ceeded by an oil, whofe colour, confiftence,
and weight, gradually increafe. From fome
vegetables, a light and fluid oil is obtained ;
but from others, a ponderous oil, capable
of becoming concrete. The fmell of this oil
is always ftrong, and empyreumatic. Dur-
ing the time it comes over, a quantity of
elaftic fluid is difengaged, which confifts ei-
ther of the cretaceous acid, or inflammable
gas, but mod commonly of a mixture of
both. At this period it is that the volatile
alkali fublimes, when the vegetable is of
fuch a nature as to afford it. When all thefe
fubftances are paft, the reiidue of the vege-
table is of the nature of coal. We fhall
now proceed to examine more particularly
into the nature and origin of each of thefe
produdts.

The phlegm is produced from the water
that enters into the compofition of the vege-
table, and partly from the water of vege-
tation, efpecially when the matter is not in^
tirely dry ; fo that its quantity is greater or
lefs on this account. The phlegm is co-
loured red, by a fmall quantity of oily matr

ter

BY DISTILLATION. 119

ter which rifes, and is ufually rendered fa-
ponaceous, by the fait contained in the
fluid. The faline matter is mod com-
monly acid ; for which reafon the phlegm
ufually reddens fyrup of violets, and caufes
an effervefcence with cretaceous alkalis.
This acid arifes from the mucilage, and the
oil. But the phlegm is fometimes alkaline, as
happens when nitrous or cruciferous plants,
or emullive and farinaceous feeds, are dif-
tilled; and it is often ammoniacal, becaufe the
volatile alkali fucceeds the acid, and com-
bines with it. This fad: may be afcertained
by the addition of a fmall quantity of quick-
lime, or alkali, by which a ftrong fmell of vo-
tile alkali will be produced, when ammonia-
cal fait is prefent. Though the acids of vege-
tables do not appear to be all of the fame
nature, thofe which are obtained, in their
diffolution, exhibit the fame external cha-
racters : but they have not yet been fuffi-
ciently examined to afcertain their properties
with any degree of accuracy. The oils ob-
tained from vegetables in this method, are
all ftrong- fmelling, highly-coloured, and
poffefs nearly the fame properties. Thofe
parts of vegetables which contain a large
quantity of thefe inflammable fluids, fuch
as the emulfive feeds, afford a large quantity
of oil in their analyiis. Odoriferous plants
afford an oil, which, at the beginning, flight-
]y partakes of their peculiar fmell, but quick-
H4 \y

120 PRODUCTS FROM PLANTS

ly aflumes the characters of other oils of this
kind, namely, colour, weight, and an em-
pyreumatic fmell. All thefe fluids are very
inflammable ; the nitrous acid fets them on
fire, and they are foluble in fpirit of wine.
They may all, by rectification, be rendered
very fluid, light, and colourlefs, and be con-
verted into the ftate of etherial or eflential
oils.

The volatile fait, or ammoniacal chalk, is
only obtained from certain vegetables ; but
it is not true, as fome chemifts have affirm-
ed, that it is afforded only by the cruciferous
plants. All plants in general, which con-
tain a certain quantity of glutinous or ve-
geto-animal matter, afford more or lefs of
volatile alkali, by virtue of the mephitis,
fhewn by Mr. Berthollet to exift in this ve-
getable principle. It is very feldom, how-
ever, that any confiderable quantity is ob-
tained in the concrete ftate, as it is ufually
diflblved in the laft portions of the phlegm.
This fait is produced by the union of the
mephitis with the inflammable gas of the
oil, and for this reafon it moft commonly
paffes over towards the end of the diftilla-
tion. It even feems, that the volatile alkali,
which rifes with the phlegm in the analyfis
of certain plants, fuch as the cruciferous
plants, poppy, rue, &c. is always the pro-
duel of a new combination ; fince Rouelle
the younger has fhewn, that the plants

them-

BY DISTILLATION. J2J

themfelves do not contain it in their natural
ft ate.

The elaftic fluids, difengaged during the
diftillation of vegetables, appear to depend
on the nature of the vegetable. A plant,
which contains a large quantity of oily com-
buftible fluid, affords inflammable gas. Mu-
cilages, on the contrary, afford cretaceous
acid. We have obferved, at the article of
the acid of fugar, that Bergman and Fontana
obtained a large quantity of cretaceous acid
from that fubftance, and that the latter che-
mift thinks, that vegetable acids are for the
moft part compofed of it. It is not, there-
fore, to be wondered, that mucilages, in
which Bergman difcovered the fame acid as
exifts in fugar, fhou Id afford cretaceous acid.
Laftly, there are fome vegetable matters
which afford atmofpheric mephitis. Thefe
aeriform fluids are not extracted till near the
end of the diftillation, when the vegetable
becomes intirely decompofed. Hales, who
was not acquainted with their nature, ob-
ferved, that the quantity of air difengaged
during the diftillation of vegetables is greater,
the more folid they are ; whence he con-
cluded, that this element was the cementing
principle and caufe of folidity in bodies. It
is eafy to form a proper opinion of this hy~
pothefis, from what has been already faid.

CHAP.

122 CHARCOAJL

CHAP. XVIIL

Of Vegetable Coal, or Charcoal.

pHARCOAL is the black refidueofve^
^ getables, which have fuffered a complete
decompofition of their volatile principles,
in clofed veflels. The property of affording
charcoal is only obferved in fuch organic
fubftances as contain the combuftible matter
called oil. The formation of coal was for-
merly attributed, exclufively, to the decom-
pofition of this lafl fuhftance ; but we begin
to perceive, that the carbonaceous matter ex-
ifts, ready formed, in vegetables, and that
the action of fire merely feparates the volatile
principles.

Charcoal in general is black, brittle, fo-
norous, and light ; it retains the form of the
vegetable, provided its. texture has been con-
fiftent, and the quantity of fluid not very
great. If, on the contrary, a foft and fuc-
culent plant be decompofed, the volatile
matters, during their difengagement, deftroy
the organic texture, and afford a friable coal,
which does not poffefs the figure of the ve-
getable. The quantities of coal vary ac-
cording to the folidity and texture of the

vegetable.

CHARCOAL. 123

vegetable. Wood affords more than herbs $
gums more than refins ; and thefe laft, more
than fluid oils. Each vegetable fubftance
appears to contain it, in different quantities,
if we confider charcoal as one of the imme-
diate principles of this kingdom.

Charcoal is a fubftance which poffeffes
very fingular properties, for the moft part
little known. Though it is of the greateft
importance in chemiflry, and exhibits phe-
nomena of the moft fingular kind, no che-
mift has yet attempted to difcover its nature
by a connected feries of inquiries. Stahl,
who attended more particularly to this fub-
ftance than any other chemift, confiders it
as the principal repofitory of phlogifton.
The knowledge we poffefs concerning the
properties of charcoal, is almoft intirely con-
fined to its economical ufes ; and the labours
of philofophers exhibit nothing which can
be called complete reflecting it. The phy-
fical properties of charcoal differ according
to the ftate and nature of the vegetable ufed
in its formation -, it is fometimes hard, and,
as we have obferved, retains part of the or-
ganization of the vegetable : other fpecimcns
are friable, and pulverulent. Pure oils af-
ford a coal, in very fine particles, known by
the name of lamp-black. Its weight va-
ries according to circumftances. When
well made, it has neither tafte nor fmell in
any fenfible degree. Its colour is alfo fub-

jed:

124 CHARCOAL.

je<ft to variation, and is of a black more
or lefs deep, either fhining or dull. But
the moft important inquiry, refpe&ing this
product of fire, relates to its chemical prin-
ciples.

Charcoal, expofed to the moft violent heat,
in clofed veffels, is not in the leaft altered.
Heated in the pneumato-chemical apparatus,
it does not afford inflammable gas, unlefs
water be prefent. A ftrong fire reduces it
into vapour. When heated with contact of
air, it burns, and is reduced to afhes, but
with peculiar phenomena, which it is ef-
fentially neceffary to diftinguifh carefully
from thofe of other combuftible matters.
When fet on fire, it becomes red, and burns
with a white flame, which is more confider-
able, the larger the mafs. It emits no kind
of fmoke, but is converted into the elaftic
fluid, cretaceous acid, which, according to
M. Lavoilier, is a combination of the car-
bonaceous and oxyginous principles, the
latter forming three-fourths of the whole.
In this manner the charcoal becomes gradu-
ally confumed, and leaves only afhes, more
or lefs white, partly faline, and partly earthy.
The different charcoals vary in their inflam-
mability; a diftinction which more parti-
cularly afcertains their utility in the arts.
Seme burn with flame, and are very quickly
confumed ; others do not take fire but with
difficulty, burn flowly, and are not reduced

to

CHARCOAL. I25

to afhes but after a long ignition. There are
fome, as for example, the charcoal of oils,
which do not burn but with the greateft
difficulty. This character feems to depend
on the adherence of the carbonaceous prin-
ciple to the fixed falts of vegetables.

Charcoal, expofed to the air, attracts humi-
dity, probably becaufe it is very porous, and
perhaps likewife by virtue of the falts it con-
tains, though they be not in a difengaged ftate.
When moiftened, it affords inflammable air,
by heat, which arifes from the decompofition
of the water; for when that fluid is paffed
in vapour through an earthen tube, filled
with red-hot charcoal, thefe two bodies are
converted into inflammable gas, and aeriform
cretaceous acid. The refidue is a fmall
quantity of afhes. Rouelle has obferved,
that fixed alkali diffolves a confiderable quan-
tity of charcoal by fufion.

The vitriolic acid, ftrongly heated with
charcoal, in powder, is decompofed by that
combuftible fubftance, which has a ftronger
affinity than fulphur with the oxyginous
principle.

The nitrous acid is much more rapidly
decompofed by charcoal. Dr. Prieftley ob-
ferved, that much nitrous gas is produced
in this mixture. Macquer found, that the
nitrous acid very fenfibly eftervefces with
this body, by the afliftance of heat. Mr,
Prouft has fucceeded in fetting fire to char-
coal,

126 CHARCOAL.

coal, by the addition of a nitrous acid, weigh-
ing one ounce four drachms and twenty-
three grains, in a bottle which held an ounce
of diftilled water. The novelty and im-
portance of his experiments are fuch, that I
fhall quote his own words, extracted from
his observations on pyrophori made without
alum, &c. inferted in the Journal de Medi-
cine for July 1778.

" Coal from the extract of carthamus, re-
€C duced to powder, and recently calcined,
€C detonated very ftrongly with the nitrous
<c acid ; and the rapidity with which the
" mixture took fire, threw up the powder
" in the form of a very beautiful fire-work.
** I calcined very fine powder of common
€C charcoal, and the detonation fucceeded
tf very well.

" I introduced about a drachm of the
" powder of charcoal into a very dry glafs
*' retort; I then poured in about a drachm
" of nitrous acid, which had no fooner
" reached the bottom of the retort, than
" the detonation took place with the great-
'* eft rapidity : a flame of more than four
" inches in length iffued out of neck of the
U retort while I held it in my hand, which
" carried with it the powder, and very
" deep-coloured vapours of nitrous acid.
" Thefe vapours condenfed into 2 green li-
" quor, fcarcely fuming : it confifted of
'f the nitrous acid, weakened by the water

" which

<<

CHARCOAL. 127

which entered into the combination of
that which detonated firft. I poured new
nitrous acid on the charcoal which re-
mained in the retort, and continued the
procefs till the whole was intirely de-
ftroyed by fucceffive inflammation.
" I repeated this experiment with cal-
94 cined lamp-black; the events were the
u fame : the retort was found to contain
" only a fmall portion of afhes, fometimes
94 femi-vitrified, and adhering to the bottom
44 of the retort.

•f All charcoals in general attract a con-
fi fiderable quantity of humidity. It ap-
44 peared to me, that charcoal calcined in
" the evening, and kept till the next morn-
44 ing, was no longer proper for thefe ex-
" periments, becaufe it became fenfibly
" moiftened in that fpace of time. But the
44 moll Angular circumftance is, that thefe
*' experiments are capricious, and do not
i€ always fucceed, though with the fame
" charcoal, the fame acid, and the fame
*• proportions. The following manipula-
tion appeared to me to infure fuccefs. If
the acid be poured in the middle of the
powder, it does not take fire : but if,
on the contrary, it be fuffered to run
down the fide of the capfule, or crucible,
fo as to occupy the lower place, the de-
tonation is made from that point; the
powder rifes and takes fire, by the nitrous

'• acid.

<c

tc

c<

<iC

128 CHARCOAL.

" acid. When nitrous acid is wanting, the
" detonation ceafes of itfelf, and the fur-
" rounding charcoal remains black."

The action of the other acids on charcoal
is not known.

This fubftance, afllfted by heat, decom-
pofes all the vitriolic falts, and forms livers
of fulphur.

Itcaufes nitre to detonate, which burns it,
by means of the pure air afforded from the fait
by the adtion of the fire. A preparation is made
for chemical and pharmaceutical purpofes,
called nitre, fixed by charcoal. Two parts
of nitre, and one of powdered charcoal, are
mixed, and thrown into a red-hot crucible
on the fire. A ftrong detonation enfues,
after which a white mafs remains, confifting
of the fixed alkali of the nitre and of the
charcoal. By lixiviating this mixture, the
water difiblves the fixed alkali, and leaves
a fubftance fuppofed to be an earth.

Liver of fulphur diffolves charcoal very rea-
dily, both by the dry and moift way, and even
combines with it more readily than any other
fubftance. This difcovery is due to Rouelle.

Metals do not unite with charcoal, but
their calces recover the metallic ftate when
heated with this fubftance. We have feen,
at the article of metals, that this phenome-
non may readily be accounted for, from the
affinity of the oxyginous principle with the
carbonaceous principle.

The

COLOURING MATTERS. 129

The action of vegetable fubftances on char-
coal has not been much examined. It is
only known, that a mixture of this fub-
ftance with fat oils renders them inflam-
mable by the nitrous acid; a circumftance
which confirms the theory of Rouelle re-
fpecting the inflammation of oils by this
acid.

All the fafts here related, concerning the
known properties of charcoal, tend to prove,
that this body is compofed of combuftible
matter, falts, and earths.

The peculiar combuftible matter which
conftitutes more than three-fourths of char-
coal, or the carbonaceous principle pro-
perly fo called, is as yet fcarcely at all
known. It appears, however, to have the
ftrongeft affinity with the oxyginous prin-
ciple, which it takes from almoft every other
body, and that in many particulars it re-
fembles plumbago.

The various uies of charcoal in the arts,
and in chemiftry, are w7ell known.

Vol. IV. I CHAP,

13° FOT-ASHt.

CHAP. XIX.

Concerning the Fixed Salts and Earths of
Vegetables.

"II7HEN a vegetable coal has been burn-
^* ed, a grey, blackifh, or white matter
remains, according to the nature of the
charcoal. This fubftance, called afhes, is
very compounded ; when well made, it con-
tains only faline and earthy fubftances, mix-
ed with iron, and a fmall quantity of man-
ganefe. When the charcoal has been burn-
ed with difficulty, the afhes ftill retain a
fmall portion of inflammable matter. M.
Lavoifier, on examining the wood afhes ufed
by the faltpetre-makers, found them to con-
tain extractive and refino-extradtive matters.
The faline fubftances obtained, by lixivia-
tion, from afhes, have been called the fixed
falts of plants. The incineration of vege-
tables is ufed for obtaining three kinds of
falts, which we fhall here defcribe.

1. Pot-afh, from which the vegetable
fixed alkali is obtained, is prepared in the
north, by burning wood, with which thofe
countries abound. This fait is very impure;
it often contains combuftible matters, which
diminish its whitenefs, and frequently neu-
tral

sbftA. 131

tral falts, fuch as the vitriols of pot-afh, of
foda, and of lime, the muriates of pot-afh
and of foda, a fmall quantity of cretaceous
foda, with iron and earthy fubflances. To
purify this fait, it is diffolved in the fmalleffc
poffible quantity of cold water. The fluid
becomes charged with the alkali, and fome
of the neutral falts 3 and the earth, the char-
coal, the iron, and the felenite, often con-
tained in pot-afh, are feparated by the filter.
This folution is then evaporated to a pellicle,
and the feveral falts it contains are fuffered to
cryflallize by cooling. After feveral filtra-
tions, evaporations, and cryflallizations, when
the lixivium no longer affords any neu-
tral fait, it is evaporated to drynefs, and cal-
cined. The fait is then cretaceous vege-
table alkali, mixed with the fame alkali in
a cauflic flate : it feems, however, always
to contain fome neutral falts, and a fmall
quantity of earthy fubflance, which is de-
pofited by {landing, and may be feparated by
the filter. After which, it may be ufed in
the nicefl chemical experiments.

2. Soda, from which the mineral alkali is
obtained, is the refidue of the combuflion
of plants that grow on the fea coafls. It is
prepared at Alicant in Spain, in Languedoc,
at Cherbourg, &c. by burning various fpe-
cies of plants. At Alicant, they ufe the
kalis ; and at Cherbourg, the algas, and
fucus, commonly known by the name of
I 2 varech.

132

SODA

varech. The firft plant contains a much
greater quantity of mineral alkali than the
fecond, which affords fcarcely any. Thefe
different plants are burned in a trench.
At Cherbourg, when the combuflion is ad-
vanced, and the afhes are very hot, they are
ftrongly agitated, and kneaded together with
large poles. By this motion, the fub-
ftance, which is fufficiently hot to undergo
a kind of femi-vitrification, takes the form
of hard and folid lumps, known in com-
merce by the name of falicore, falicote, la-
marie, and alun catin. The names, by which
it is more particularly diftinguifhed, denote
either the plant from which it was obtained,
or the country where it was made. The
foda of Alicant, likewife called barilla, is
the beft for chemical purpofes, and thofe arts
which require much mineral alkali. The
foda of Cherbourg, or of varech, contains
lefs alkali, and ought not to be ufed in che-
mical experiments ; but it is advantage-
oufly ufed in the manufacture of glafs, be-
caufe the viti*eous frit it affords is found to
be very ferviceable in that manufacture.

The foda of commerce, chemically con-
fidered, is a compound of cauftic foda, cre-
taceous foda, cretaceous vegetable alkali in
a fmall quantity, vitriols of pot- afh and of
foda, marine fait, charcoal, iron in the ftate
of Pruffian blue, according to the obfervation.
of Henckel, and earth, partly difengaged, and

partly

FIXED SALTS. I33

partly combined with fixed alkali, as in that
of Cherbourg. To feparate thefe fubftances,
and obtain pure cretaGcous foda, it is dif-
folved in cold diftilled water, and filtered, to
feparate the earth, iron, and coaly matter;
after which it is evaporated, as we have ob~
ferved concerning pot-afh. This alkali is
purified more eafily than that of pot-afh,
becaufe, as it cryftallizes more readily, it
can be better feparated from the portion of
cauftic foda; yet it contains fome of the neu-
tral falts, and Pruffian blue, when firft cryf-
tallized, which muft be feparated by repeated
folutions and cryftallizations.

3. Fixed falts are prepared in pharmacy,
which have been greatly recommended by
Tachenius, and are ftill diftinguifhed by his
name. The procefs of this chemift confifts
in placing the plant, whole fait is propofed
to be obtained, in an iron pot. This veffel
is heated till its bottom is red hot; the
plant, which is continually ftirred, emits
much fmoke, and takes fire, at which time
the pot is covered, (o that the fmoke may be
diflipated, and the flame extinguifhed. By
this means, the plant is gradually confumed.
When reduced to a kind of blackifh afhes, it
is lixiviated with boiling water, which af-
fords a yellowiih, or brown fait, by evapo-
ration to drynefs. This fait is often alka-
line, but is very impure ; it is coloured by
much extractive matter, which is mixed with

I 3 all

134 RESIDUES OF

all the neutral falts the plant contained. As
it is a faponaceous compound, good effects
often follow its ufe ; but it cannot be fup-
pofed to poffefs the fame virtues as the plant
from which it was extracted, becaufe its
principles have neceffarily been altered by
the combuftion. It would be of confiderable
ufe to examine, analytically, the different
fixed falts of plants, prepared after the man-
ner of Tachenius, in order to difcover the
faline and extractive matters they contain,
and to determine their virtues, and the dofe
in which each ought to be adminiftered.

4. When all the faline matter is warned
off from the afhes of vegetables, the remain-
der is a pulverulent fubftance, more or lefs
white, or coloured, infipid, infoluble in wa-
ter, and hitherto coniidered as an earthy
fubftance.

Iron may be extracted from this refiduum
by the magnet. This metal, as well as the
manganefe which vegetable afhes have lately
been found to contain, exifted, ready formed,
in the vegetable. Many philofophers have
fuppofed, that the colours of plants are pro-
duced by iron. Mr. Baume, who, in his
memoir concerning clays, has mentioned the
earthy refidue of vegetables, affirms, that it
forms alum with the vitriolic acid, and like-
wife felenite, flightly differing from that
which is produced by pure calcareous earth.
The other acids afford, with this refidue,

fpathofe

BURNED PL,ANTS. I35

fpathofe falts, and a fmall portion of martial
falts. Hence Mr. Baume thinks that the
earth of vegetables confifts of clay, and an
earth refembling calcareous earth, though it
feniibly differs from it, according to him, in
not forming quick-lime by the action of fire.
He thinks, that the clay is formed in thefe
organized fubftances by the collifion to which
vitrifiable earth is expofed, and the action
of acids with which it combines ; that the
clay, once formed, paffes to the ftate of cal-
careous earth, by fucceffive elaborations in
the tubes of vegetables.

We may here obferve, that the difcoveries
made in Sweden, on the faline nature of
bones, which appear to be the fame with
refpecl to animals as the fibrous parts are in
vegetable fubftances, render it probable, that
this refidue is far from being merely an earth.
An accurate analyfis, fuch as has not hither-
to been made, may {hew, that this fuppofed
earthy fubftance is calcareous phofpate j at
leaft we may fufpect this to be the cafe, fince
the experiments of Margraaf and Berthollet,
who have obtained phofphorus from muf-
tard feed, from gluten, and from feveral
Other vegetable fubftances.

I 4 CHAP.

I36 FERMENTATION*

CHAP. XX.

Concerning Fermentation in general, and
the Spirituous Fermentation in particular.

A FTER having confidered vegetables in
■*** the ftate in which they naturally exift,
we mail proceed to defcribe the changes they
experience in different circumftances. Thefe
alterations, which intirely depend on their
nature, are always the confequence of a phe-
nomenon called fermentation.

Fermentation is a fpontaneous commo-
tion in a vegetable fubftance, by which
its properties are totally changed. This
commotion is peculiar to the fluids of or-
ganic matters; no other fubftances, except
thofe which have been elaborated by the
principle of vegetable or animal life, being
fufceptible of it. Chemifts have not fuffi-
ciently attended to this important truth,
whofe application to the phenomena which
take place in organized bodies, cannot but
be of the greateft ufe in medicine.

There are feveral circumftances required
in order that fermentation may proceed.
Such are,

1. A

FERMENTATION. I37

1. A certain degree of fluidity : dry fub-
flances, in fad:, do not ferment at all.

2. A certain degree of heat. Each kind
of fermentation requires a due degree of
heat, but cold flops the progrefs of every
ferment.

3. The contact of air. On this account
it is, that organized fubftances are very well
preferved, and are not altered in a vacuum.

Chemifts, after Boerhaave, have diftin-
guifhed three kinds of fermentation : the
fpirituous, which affords ardent fpirit ; the
acetous, which affords vinegar, or acid ; and
the putrid fermentation, or putrefaction,
which produces the volatile alkali. It muft
be obferved, that there are many fermenta-
tory proceffes which do not feem to belong
to thefe three kinds ; fuch, perhaps, are the
fermentations of bread, of mucilages, that
which developes the colouring parts, &c.
It has been thought, that the fermentations
always follow each other in the order we
have mentioned ; but there are bodies which
become acid, without having previoufly un-
dergone the fpirituous fermentation -y and
there are others which putrify without paffing
through the two firft ftages. We may like-
wife obferve, that the inteftine motion of
maturation appears to conftitute a kind of
fermentation, by which faccharine matter is
produced or difengaged.

The fpirituous fermentation, or that which

produces

I38 SPIRITUOUS FERMENTATION.

produces ardent fpirit, may be confidered
with refpedt to, 1. The conditions neceffary
to its production ; 2. The phenomena which
accompany it; 3. The leveral fubftances
fufceptible of this fermentation ; 4. Its
caufe; and, 5. Its products.

Experience has (hewn, that all vegetable
matters are not capable of paffing to the fpi-
rituous fermentation, but that the union of
feveral peculiar circumftances is neceffary for
this purpofe,

Thefe conditions are, 1. A faccharine
mucilage. This fubftance only is capable
of paffing to the fpirituous fermentation.

2. A degree of fluidity, flightly vifcid.
If the vegetable fluid be either too thick, or
too thin, it will not ferment,

3. A degree of heat, from ten to fifteen
degrees of Reaumur's thermometer, or be-
tween fifty-five and fixty-five of Fahrenheit.

4. A large mafs, in which a rapid com-
motion may be excited.

When thefe four conditions are united,
the fpirituous fermentation takes place, and
is known by the following characteriftic phe-
nomena.

1 . An inteftine motion is excited in the
liquor, which increafes till the fermentation
is well eftablifhed.

2. The bulk of the mixture is quickly
augmented, and this augmentation follows
the progrefs of the inteftine motion.

3. The

SPIRITUOUS FERMENTATION, I39

3. The tranfparency of the fluid is dimi-
nished by opake filaments, which are agitat-
ed, and carried to every part of the fluid.

4. A degree of heat is produced, equal to
eighteen degrees, (feventy-two and a half
Fahrenheit) according to the Abbe Rozier.

5. The folid parts, mixed with the li-
quor, rife and float, in confequence of the
difengagement of elaftic fluid.

6. A large quantity of cretaceous acid gas
is difengaged. This gas forms a ftratum in
the upper part of the fermenting vats, which
may be ealily diftinguifhed from air. In
this ftratum it was, that Dr. Prieftley and
Due de Chaulncs made their valuable ex-
periments. Candles, plunged in this ftratum,
are extinguished, and animals die therein ;
lime-water is precipitated, and cauftic alkalis
cryftallize perfectly. This acid, contained
in the fermenting vats of brew-houfes, fre-
quently produces the moil fatal effects on
the workmen.

7. The difengagement of this gas is ac-
companied with the formation of a great
number of bubbles in the vifcid liquor,
through which the cretaceous acid mull
pafs.

All thefe phenomena gradually ceafe, in
proportion as the liquor lofes its fweet and
mild tafte, and becomes brifk, penetrating,
and capable of producing intoxication.

Neceflity has induced mankind to prepare

fermented

140 SPIRITUOUS FERMENTATION.

fermented liquids with a great number of
different vegetable fubftances ; but experi-
ence has fhewn, that faccharine matters
alone are capable of forming this kind of
fluid. The following being moft commonly
ufed, require to be enumerated.

1. The juice of grapes produces wine,
properly fo called : it is the beft of all fer-
mented liquors. The art of cultivating
vines, which is of great importance, requires
an attention to the following objects. 1.
The nature of the foil. It is known, that
a dry foil is in general well adapted to this
plant, and that a ftrong foil does not agree
with it. 2. The cultivation of this vege-
table. It is pruned; its branches are bent,
to impede the courfe of the fap ; care is taken
that it be expofed to the heat of the fun,
and more efpecially to the heat reflected from
the earth, &c. It is not manured, &c. 3.
The hiftory of its vegetation, its expofi-
tion, its flowering, the formation and ripen-
ing of the grape. 4. The accidents to which
it is expofed, fuch as froft, heavy rain, moif-
ture, &c. 5. The time of vintage, which
fhouid be dry and hot. Thefe preliminary
circumftances being known, the art of mak-
ing wine is to be confidered, which coniifts
in putting the ilalked grapes into a veffel,
expofed to a heat of fifteen or fixteen de-
grees, to break, agitate, and turn them over.
When the fermentation is excited, and all its

phenomena

SPIRITUOUS FERMENTATION. 141

phenomena take place, the juice of grapes,
or muft, mould be neither too fluid, nor too
thick ; in the firft cafe, it requires to be thick-
ened by boiling; in the latter, it is diluted
with water. When the wine is made, it is
drawn off into cafks, which are left open,
where it experiences a fecond infenfible fer-
mentation, by which its principles are more
intimately combined ; a fine lye, and a fait,
known by the name of tartar, being preci-
pitated. To preferve the wine, rags, dipped
in fulphur, are burned in the cafk which
contains it.

The knowledge of the different kinds of
wine is an object of confiderable importance.
France produces a great number of excellent
wines. Thofe of Burgundy are preferable
to any other for conftant ufe, becaufe their
principles are perfectly combined, and no
one predominates over the other. The
wines of the province of Orleans refemble
thofe of Burgundy, when they have been
matured by keeping, which combines the
excefs of ardent fpirit they contain with their
other principles. The red wines of Cham-
paigne are excellent, and of a delicate fla-
vour. The white wine of this province,
which does not fparkle, is to be preferred
to the fparkling wine, whole penetrating and
fubacid tafte, as well as its property of
fparkling, depend on the cretaceous acid
contained in it, when bottled before the fer-
mentation

14^ SPIRITUOUS FERMENTATIONi

mentation was finifhed. The wines of Lari-*
guedoc and Guienne are of a deep colour*
and are excellent bracers and ftomachics,
efpecially when of a good old age. The
wines of Anjou are white, very fpirituous,
and intoxicate quickly.

As to foreign wines, thofe of Germany,
known by the name ofRhenifh and Mofelle,
are white, and very fpirituous ; their tafte
is keen and penetrating, and they quickly
produce intoxication. Some wines of Italy,
fuch as thofe of Orvieto, Vicenza, the
Lachryma Chrifti, &c. are well fermented,
and refemble the good wines of France.
Thofe of Spain and of Greece are in general
fweet, crude, imperfectly fermented, and
very unwholfome. We muff, however, ex-
cept thofe of Rota and Alicant, which are
with juftice efteemed to be ftomachic and
cordial.

2. Apples and pears afford cyder and
perry. This fpecies of wine is very good,
and affords good brandy, as M. d'Arcet has
fhewn.

3. Cherries afford a tolerable good wine,
from which a kind of brandy is diftilled,
called Kirchenwaffer by the Germans.

4. Apricots, peaches, and plumbs, afford
a wine of inferior quality.

5. Sugar, diffolved in water, ferments
readily : from this kind of wine, a fpirit,
called rum, taffia, guildive, &c. is made.

6. The

SPIRITUOUS FERMENTATION. I43

6. The feeds of gramineous plants, and e-
fpecially barley, afford a fpecies of wine, call-
ed beer. The art of brewing confifts in the
following proceffes. Barley is fteeped in
water for thirty or forty hours, after which
it is laid in a heap, to fprout or germinate ;
it is then dried in a kiln, and the buds fe-
parated by lifting ; after which it is coarfe-
ly ground, and is diftinguifhed by the name
of malt. A certain quantity of malt is put
into a veffel, called the mafh-tun, on which
water, nearly boiling-hot, is poured, which
diffolves the mucilage. This being drawn
off, a fecond quantity of heated water is
poured on the malt, and in like manner
drawn off. This fluid, called wort, is
boiled up with hops, and is put, together
with yeaft, into a veffel, called the cooler.
When the fermentation begins to fubfide,
the beer is ftirred up, and drawn off into
calks ; the fecond fermentation throws up
a fcum, called yeaft, which ferves to ex-
cite fermentation in future brewings. The
germination developes a faccharine matter in
the barley, to which it owes its property of
forming wine : the fame procefs fucceeds
with moft other gramineous feeds.

The whole of thefe facts prove, that the
faccharine matter is the only principle of
vegetables capable of pairing to the fpirituous
fermentation, and that water is neceffary for
the production of this inteftine motion. M.

Lavoifier

144 SPIRITUOUS FERMENTATION.

Lavoifier thinks, that this fluid is decom-
pofed in the operation : the oxyginous prin-
ciple feizes the carbonaceous matter of the
fugar, and forms cretaceous or carbonaceous
acid, which is difengaged during this fer-
mentation ; while the bafe of the inflam-
mable gas unites with the oil of the faccha-
rine fubftance, and forms a very light com-
buftible fubtle body, containing much lefs
carbonaceous matter than the fugar, and
much more inflammable : this is ardent
fpirit.

The product of all thefe fermenting fub-
ftances, is a liquor more or lefs coloured,
of an aromatic fmell, a penetrating and hot
tafte, which, in fmall dofes, aflifts the action
of weak fibres, but produces intoxication
when taken too largely. It is univerfally
known by the name of wine.

The wine of grapes, for example, is com-
pofed of a large quantity of water, ardent
fpirit, an effential fait called tartar, and an
extracto-refinous matter, which produces the
colour in red wines.

Before wx proceed to defcribe the methods
of feparating thefe fubftances, it will be
proper to defcribe the ufes and properties of
the fluid itlelf. Wine diflblves many fub-
ilances, by virtue of the water, the ardent
fpirit, and the effential acid fait, of which
it is formed. It unites with extracts, refins,
certain metals, &c. On thefe properties

depend

WINE* J45

depend the preparations of medicinal wines,
fuch as, 1 . Emetic wine, prepared by ma-
cerating four ounces of crocus metallorum
in two pounds of good white wine; the li-
quid is filtered, or is ufed without filtration,
in paralytic or apoplectic cafes. 2. Chaly-
beat wine, made by digefting one ounce
of Heel filings with two pounds of white
wine : it is an excellent tonic and aperitive
medicine. 3. The wines of vegetables, pre-
pared (a) either with red wine, in which
aftringent or aromatic plants are macerated ;
(b) or with white wine, which is ufually em-
ployed with antifcorbutic plants ; (c) or with
Spanith wine : the wine of Squills, and alfo
the liquid laudanum of Sydenham, are pre-
pared with this wine. The latter is made by
digefting two ounces of fliced opium, one
ounce of faffron, a drachm of powdered
cinnamon and cloves, in a pound of Spanifh
wine. This medicine is a very good feda-
tive, taken in the dole of a few drops, efpe-
cially in cafes in which it is feared that opium
may weaken the patient, or flop fome ufeful
evacuation.

The a&ion of fire is commonly ufed to
decompofe wine, and feparate it into its feve-
ral principles. The diftillation is performed
in an alembic of tinned copper, to which a
receiver is adapted : as foon as the wine
boils, a colourlefs fluid, flightly opake, and
milky, of a hot and penetrating tafte, and a

Vol. IV, K ftrong

I46 WINE.

ftrong agreeable fmell, comes over. This
fluid is received, till the vapours no longer
take fire by a candle. It is called brandy,
and confifls of water, ardent fpirit, and a
fmall portion of oil, which renders it milky
at firft, and after a certain time colours it
yellow. The colour of old brandy, in com-
merce, does not, however, arife from the
oil alone, which comes over in the diftilla-
tion, but likewife from the extra&ive mat-
ter it takes from the cafk in which it is con-
tained. Brandy is the fluid from which ar-
dent fpirit is extracted, as we fhall hereafter
fee. The refidual liquor, after it has afforded
fpirit of wine, is of an acid aufiere tafte,
turbid, and depofits a large quantity of fa-
line cryftals, which appear to be tartar.
The wine is therefore intirely decompofed,
and cannot be reftored to its former proper-
ties by combining the fpirituous produd:
with the refidue. Hence the analyfis ap-
pears to be complicated. If the refidue of
wine which has afforded brandy be evapo-
rated, it takes the form and confiftence of
an extradl. The colouring part may be fe-
parated by the addition of fpirit of wine,
which does not adt on the tartar. Water does
not precipitate this tindlure. By evaporation
of the tindture to drynefs, a refidue is obtain-
ed, which quickly takes fire, and is foluble in
water; it is a true refino- ex tractive fub-
ftance, which the ardent fpirit, formed by

fermen-

WINE. 147

Fermentation, has extracted from the fkins
of the grapes. From this analyfis it appears,
that wine confifls of water, ardent fpirit,
tartar, and colouring matter; we have al-
ready explained the nature and properties of
two of thefe fubftances, namely, water, and
the colouring extract ; ardent fpirit and tartar
remain, therefore, to be treated of.

Before we proceed to fpeak of thefe, we
(hall take notice of a fubflance that precipi-
tates from wine during its fermentation, and
is called lees. It confifls of the feeds and
fkins of grapes, impure tartar, and vitrio-
lated tartar. By diftillation with a naked
fire, it affords brandy : treated in a retort,
it affords acid phlegm, oil, volatile alkali,
and its coal contains cretaceous vegetable
alkali and vitriolated tartar. The incinera-
tion of the lees of wine, in the open air,
affords a cauftic fixed vegetable alkali, mix-
ed with vitriolated tartar, and known in
commerce by the name of cendres gravelees.
The account we fhall proceed to give of
fpirit of wine, and of tartar, will complete
what remains to be faid concerning the lees
of wine.

K 2 CHAP*

ARDENT SPIRIT.

C PI A P. XXI.

Of Ardent Spirit, or the Product of the
Spirituous Fermentation.

WE have feen that brandy, obtained by
diftilling wine with a naked fire, is a
compound of ardent fpirit, water, and a
fmall portion of oil. Diftillation is ufed to
feparate thefe fubftances, and to obtain ar-
dent fpirit in a ftate of purity. There are
feveral methods of diftilling fpirits of wine.
M. Baume advifes to diftill brandy a con-
fiderable number of times, by a water-bath,
to obtain 'all its fpirit. He recommends the
feparation of the firft fourth part of the pro-
duct of the firft diftillation, and likewife of
the firft half of the product of the following
diftillation s; to mix all thefe together, and
to rectify by a gentle heat. The firft half
of the fluid, which paffes in this rectification,
is the pureft ardent fpirit, called alkohol;
the remainder is lefs ftrong, but very good
for ordinary purpofes. Rouelle directs, that
half the brandy made ufe of, be drawn off
by diftillation on the water-bath ; this firft
product is common fpirit of wine, which,
being rectified twice, and reduced to about

two-

ARDENT SPIRIT, 149

two-thirds, becomes a flronger fpirit. This
is to be again diftilled with water, according
to the procefs of Kunckel, which feparates
the oil > the diftilled fpirit, being again rec-
tified, may be depended on as perfectly pure.
The refidue of brandy, after diftillation, is
water, containing colouring matter, on the
top of which a peculiar oil floats.

Hence it may be obferved, that the pu-
rity and ftrength of ardent fpirit muft differ
according to the proceffes ufed in obtaining
it. A method of difcovering its purity has
long been fought after. It was formerly
fuppofed, that fpirit of wine, which readily
catches fire, and leaves no refidue, is very
pure; but it is at prefent well known, that
the heat excited by its combuftion is fuffi-
ciently ftrong to diiiipate all the phlegm it
might contain. Another proof has been
propofed, by means of gunpowder : when
fpirit of wine, let on fire in a fpoon upon
gunpowder, does not inflame it, it is con-
iidered as bad ; if, on the contrary, it fets
it on fire, it is judged to be excellent. But
this proof is very fallacious ; for when a
large quantity of the beft fpirit of wine is
burned on a fmall quantity of gunpowder,
the water it affords during its combuftion
moiftens the powder, and prevents its taking
fire; whereas it may be inflamed by burn-
ing a very fmall quantity of phlegmatic fpirit
of wine on its furface. This method is
K 3 therefore

150 ARDENT SPIRIT.

therefore no more to be depended on than tho
former. Boerhaave has defcribed a very
good procefs for afcertaining the purity of
this fluid : it confirts in throwing the very
dry powder of fixed fait of tartar into fpirit
of wine ; this unites with the fuperfluous
water of the fpirit, and forms a more pon-
derous and coloured fluid than the ardent
fpirit, with which it does not mix, but falls
to the bottom. Laftly, M. Baume, on the
confideration that fpirit of wine is lighter
the purer it is, has contrived an areometer,
by which the degree of purity of this fluid
may be accurately afcertained. When the
inftrument is plunged in fpirit of wine, it
links deeper, in proportion as the fluid is
purer. By experiments carefully made, he
has determined, that the pureft and moft
highly rectified fpirit of wine gives thirty-
eight degrees of his areometer. The me-
thod of constructing this inftrument, as well
as the refults afforded by different quantities
of fpirit of wine, may be {ten in his ele-
ments of pharmacy, and may be applied to
determine the ftrength of fpirit of wine by
the hydrometer.*

Pure

* Notwithstanding the labours of many ingenious che-
mifts, and particularly thofe of Mr. Bories, related in his
Memoir, which obtained the prize propofed by the ftates
of Languedoc, in 1772, and publifhed at Montpelier in
the year 1774, much remains to be done before the

ftrength

ARDENT SPIRIT. 151

Pure ardent fpirit, obtained by the procefs
we have defcribed, is tranfparent, exceedingly
fluid, and fo light, that it weighs four hundred
and eighty grains, in a bottle which contains
five hundred and feventy fix grains of diftilled
water. Its fmell is penetrating, and agreeable ;
its tafte is hot, and ftrong. It is extremely
volatile, rifing and paffingover in clofe veiTels,
by a very gentle heat, and is by this means
K 4 feparated

ftrength of fpirits can be determined, with fufficient accu-
ra :y e\en fcr commercial purpofes. If ardent fpirit, which
is fo highly dephlegmated as not to liquefy hot pulverized
all: di, be confidered as pure fpirit, or the ftandard extreme,
diftilled wacer forming the other extreme, it will then be
necelTar^ to afcertain, by experiment, \. The fpeciflc
graviry of 1 certain number of mixtures of water and this
f, irit, taken fo near each other, as that the intermediate
fpecmc gravities may not fenfibly differ from thofe deduced
mathematically in the ufual manner. 2. The expanfions,
or variations of fpeciflc gravity of thefe mixtures, at the
different temperatures of the atmofphere. 3. The change
of fpeciflc gravity, produced by the folution of faccharine
or oleaginous fubltances in thefe fpirits. 4. Eafy methods
muft be devifed to mew the prefence and quantity of
the laft mentioned fubftances ; and alfo, 5. To deter-
mine the fpeciflc gravity of the fluid.

Thefe requifites demand a great number of accurate
experiments to be made. Rectified ardent fpirit, re-
peatedly affufed on dry alkali, till it would no longer
diffolve or liquefy it, was found, by Mr, Bories, by many
experiments, to have the following fpeciflc gravity.

Reaumur's Therm. 4- ro°==82o||||
* i5°=8i75i!s

4* 20°=8i3|48

05s

Th(

152 ARDENT SPIRIT.

feparated from the fmall quantity of water
it might contain. The firft portions are the
moft volatile, and pure. It was formerly
thought, that a large quantity of air was
always difengaged during the diftillation
of fpirit of wine. This fuppofed air is
now. known to be the fpirit itfelf, in the
form of gas.

When ardent fpirit is heated with the
contact of air, it foon takes fire, and exhi-
bits a light flame, white in the middle,
and blue at the fides ; it completely burns
away, when pure. Many chemifts have at-

The fpecific gravities of mixtures, by meafure, of the
foregoing fpirit with diftilled water, were as under.

Temperature »J- 150 Reaumur.

Spirit 10 Water o Specific gravity 8i7sI!t

9 - - - 1 844!ot!

8 - - - 2 869SII

7 - - - 3 893HH

6 4 91STW?

5 - - " "5 934T-J35f

4 - - - 6 I ----- . 95"i?!l

3 7 9<>S\V&

2 - - 9 976^||

1 - - - 9 - 987t7oYt

O - - - IO ----- 1. 000

I find, by diftilling 20 meafures of the beft fpirit of wine
of the ftiops, (Sp. Gr. = 836) in glafs veffels, by a lamp,
that the firft meafure which came over had a fpecific gravity
of 820, at a temperature of 710 of Fahrenheit, or about
»J- 1 7 1 of Reaumur. This, which is the ftrongeft fpirit
mere diftillation can afford, contains about one part in the
hundred of water, of which it may be deprived by alkali.
Note of the Tranflator.

tempted

ARDENT SPIRIT. 1 53

tempted to difcover the product afforded by
fpirit of wine in burning. They found that
its flame is accompanied with neither foot
nor fmoke ; and that the volatilized matters
when condenfed, are pure water, without
tafte or fmell, abfolutely in the ftate of dif-
tilled water. Boerhaave, from this pheno-
menon, fuppofed, that the flame is pro-
duced by the water ; and this opinion is
confirmed by the knowledge we at prefent
poflefs, refpecting the inflammable air ob-
tained by the decompoiition of water, and
the water obtained by burning inflammable
gas. Mr. Lavoifier difcovered, that when
fpirit of wine is burned in a chimney a-
dapted to receive the vapours, a larger quan-
tity of water is obtained than the whole
of the fpirit made ufe of amounts to; whence
it follows, that this liquor contains a large
quantity of inflammable gas. On the other
hand, Mr. Berthollet has remarked, that
when a mixture of this fpirit and wrater is
burned, the refidual fluid precipitates lime-
water. This experiment fhews, that ardent
fpirit contains a fmall quantity of carbona-
ceous matter, which, by its combuftion or
combination with the oxyginous principle,
forms the cretaceous acid. Chemifts have
adopted different opinions reflecting ardent
fpirit ; Stahl, Boerhaave, and fome others,
have coniidered this fluid as a compound of
a very attenuated oil, a fubtle acid, and

water.

154 ARDENT SPIRIT.

water. Others, at the head of whom may-
be placed Cartheufer and Macquer, think that
fpirit of wine is formed by the union of
phlogifion and water. The nature of this
fluid is not yet well known. Spirit of
wine, expo fed to the air, evaporates at a
temperature of 550, and leaves no refidue,
except a ftnall quantity of water, when it
has not been well dephlegmated. This eva-
poration in the air is more rapid, the hotter
the atmofphere ; and produces a degree of
cold, which is ftronger in proportion to its
rapidity. Spirit of wine has the form of an
elaftic fluid at 185 degrees of Fahrenheit's
thermometer.

Spirit of wine unites with water in all
proportions, and is perfectly foluble in that
fluid. This folution is attended with heat,
and produces mixtures, whofe ftrengths are
greater in proportion as the quantity of ar-
dent fpirit is greater. The affinity of com-
bination between thefe two fluids is fo
ftrong, that water is capable of feparating
fpirit of wine from many bodies with which
it may be combined -y and on the contrary,
fpirit of wine decompofes moft faline folu-
tions, and precipitates the falts. From the
confideration of this laft property, it is, that
Boulduc propofes the ufe of fpirit of wine to
precipitate the falts contained in mineral
waters, and to obtain them unaltered.
Spirit of wine has no aftion on pure

earths.

ARDENT SPIRIT. 155

earths. It is not known whether it is al-
tered by ponderous earth and magnefia. Lime
appears capable of producing fome change
in this fluid, fince it acquires a degree of
fmell when diftilled from that earthy fub-
ftance. But this alteration has not been
properly inquired into.

Fixed alkalis appear really to decompofe
fpirit of wine, as is known by the medical
preparation called the acrid tincture of tar-
tar. To prepare this, pot-aih is melted in
a crucible, pulverized while hot, and put
into a matrafs ; highly dephlegmated fpi-
rit of wine is poured on, to three or four
fingers depth ; the matrafs is clofed with
another of a fmaller iize, luted together,
and the whole is digefted on a fand bath,
till the fpirit has acquired a reddifli colour.
A great or lefs quantity of alkali remains at
the bottom of the veflel. This acrid tinc-
ture of tartar affords, by diftillation, a fpirit
of wine of a fweet fmell, fcarcely altered ;
and a fubftance remains in the retort re fern -
bling a faponaceous ex t raft, which diftilled
with a naked fire, affords fpirit of wine,
volatile alkaline fpirit, and a light empyreu-
matic oil. In this operation, a fmall quan-
tity of charcoal is formed, which is found
to contain the vegetable alkali. The ex-
periment feems to (hew, that fpirit of wine
contains an oil which is feized by the fixed
alkali, and forms a true foap kept in fo-

lution

I56 ARDENT SPIRIT.

lution in the portion of ardent fpirit which
is not decompofed. The lilium of Para-
celfus does not differ from the acrid tincture
of tartar, excepting that the fixed alkali
employed in its preparation appears to be
rendered cauftic by the metallic calces with
which it was heated. The martial, jovial,
and cupreous reguli of antimony, each in
the quantity of four ounces, are fufed toge-
ther, then reduced into powder, and detonated
with eighteen ounces of tartar, and as many
of nitre; the whole being melted, pulverized,
and put into a matrafs, highly rectified fpi-
rit of wine is poured on, to the height of
three or four inches above the mixture. By
digeflion on a fand bath, the fpirit aiTumes
a beautiful red colour, deeper than that of
the preceding tincture, but prefenting the
fame phenomena. The former tindture may
be made intirelv fimilar to the lilium of
Paracelfus, by digefting fpirit of wine in
the cauftic fixed alkali, inftead of ufing
fait of tartar, which is not deprived of its
cretaceous acid, unlefs it has been kept red
hot a long time. Mr. Berthollet afcertained
that thefe tinctures are merely folutions of
cauftic vegetable alkali in fpirit of wine,
and that they afford an ufeful method of ob-
taining the alkali very pure, by evaporation
of the fpirit. Spirit of wine has the fame
action on pure foda. The acrid tinctures of
tartar are excellent bracers, and powerful

deobflruents.

ARDENT SPIRIT. I57

deobflruents. They are ufed in thofe cafes
where the natural forces of the patient are
infufficient to favour the crifis, as in the
malignant fever, the worft kind of fmall
pox, &c.

The action of the cauftic volatile alkali
on fpirit of wine has not yet been exa-
mined.

All the acids prefent very important pheno-
mena with this fpirituous fluid. When con-
centrated oil of vitriol is poured on an equal
quantity of rectified fpirit of wine, a ftrong
heat, with a remarkable hilling noife, is
produced ; the two fubftances become co-
loured, and emit a fweet fmell, refembling
that of lemon-s, or the apple called golden
rennet. If the retort, in which this mix-
ture is ufually made, be placed on a fand
bath with large receivers adapted, the firft
being plunged in a vefiel of cold water, the
products are, 1 . A fpirit of wine of a fweet
fmell. 2. A fluid called ether, of a very
agreeable fmell, extremely volatile, whofe
prefence is afcertained by the ebullition of
the liquor contained in the retort, and by
the large ltrias which run down the fides of
the vefiel. The receiver muft now be kept
cool by wet cloths. 3. After the ether, a
fulphureous fpirit paffes, whofe white colour
and fmell indicate the proper time for chang-
ing the receiver, in order to have the ether
feparate, 4. At the fame time a light yel-

lowifh

158 Ether.

lowifh oil is volatilized, which is called
fweet oil of wine. The fire muft be greatly
lowered after the ether is paffed, becaufe the
matter contained in the retort is black, thick,
and fwells up confiderably. 5. When the
fweet oil is all diftilled, fulphureous acid
next comes over, which becomes thicker
and thicker ; and towards the end dirty and
black oil of vitriol. 6. The operation be-
ing continued by a gentle heat, the refidue
becomes perfectly dry, and has the form and
confidence of a bitumen. By expofure to a
flrong heat, an acid liquor and a dry and yel-
lowifh fubflance refembling fulphur, is ob-
tained. M. Baume, who has made a great
number of experiments on vitriolic ether,
has very carefully examined this refidue,
and found it to contain martial vitriol, Pruf-
lian blue, a faline fubflance, and a peculiar
earth, whofe nature he has not afcertained.
He even affirms, that the yellowifh fubli-
mate it affords, is not fulphur, but that it
remains white and pulverulent, without
taking fire on the coals. To thefe details
we fhall add, that the refidue of ether af-
fords new ether, by the addition of one-
third of fpirit of wine dephlegmated by fait
of tartar, and diflilling the mixture, as Mr.
Cadet has fhewn. Thefe diilillations may
be repeated feveral times, and from a mix-
ture of fix pounds of oil of vitriol and fpirit
of wine, to which fifteen pounds of the lat-
ter

ETHER. I59

ter fluid are fucceflively added, more than
ten pounds of good ether may be obtained.
The operation we have described, is one
of the moft fingular in chemiftry for the
phenomena it exhibits ; and at the fame
time one of the moft important, with refpedt
to the explanation it affords concerning the
compofition of fpirit of wine. There are
two opinions refpe<5ting the formation of
ether, which it is neceffary to explain.
Macquer, who, as we have obferved, con-
fiders fpirit of wine as a compound of water
and phlogifton, thinks that the oil of vitriol
takes the water from this fubftance, and
caufes it to approach gradually to the cha-
racters of oil. According to this opinion,
therefore, fpirit of wine firft paffes over
icarcely altered ; next a fluid, which occu-
pies the middle place between water and oil ;
and laftly, a true oil, becaufe the vitriolic
acid a<5ts fo much the ftronger on the
principles of the fpirit of wine, as the heat
is more confiderable. Bucquet made a
ftrong objection to this theory ; namely,
that it is difficult to conceive, how the
oil of vitriol, charged from the firft with
a certain quantity of water it had taken
from the fpirit of wine, could ftill, not-
withstanding this dilution, re-adt fo ftrong-
ly on a portion of the fame fpirit, as to
put it into the oily ftate. He therefore
propofed another opinion refpeCting the pro-
duction

l6o ETHER,

dudiion of ether. He confidered fpirit of
wine as a fluid compofed of oil, acid, and
water ; and imagined, that when the acid
of vitriol is mixed with the fpirit, a kind
of bituminous fluid is produced, which af-
fords by heat the fame principles as all bitu-
mens ; namely, a light, odorous, very com-
buftible oil, or a fpecies of naptha, which
is the ether, and afterwards a lefs volatile
and more coloured oil, which is the fweet
oil of wine. We mall, in fact, perceive by
the properties of ether, which we are about
to explain, that this fluid has all the cha-
racters of a highly attenuated oil, fuch as
naptha. This theory does not explain,
with fufficient perfpicuity, what happens
during the preparation of ether. The oxy-
ginous principle appears to be taken from
the vitriolic acid by the fpirit of wine, and
to be one of the principles of the ether.

Ether obtained by the procefs we have
defcribed, is not in a Hate of purity, but
contains fpirit of wine and fulphureous acid.
It muft be rectified by diftillation in a retort,
on a fand bath, with the addition of fixed al-
kali. The fait combines with the fulphu-
reous acid, and the ether palfes over in a
ftate of great purity, by the gentleft heat.
The firft part of this product being received
feparate, is the pureft and mod highly rec-
tified ether.

Ether is a fluid much lighter than fpirit

of

ETHER. l6l

of wine, of a ftrong, fweet, and very ex-
panfible fmell, of a hot and penetrating
tafte. It is fo volatile, that it is inftantly
diffipated by agitation, or pouring out.
During its evaporation, it produces a de-
gree of cold fufficient to freeze water, as
M. Baume has (hewn in his experiments.
It takes the form of gas, which burns with
great rapidity. Air, which holds ether in
folution, may be paffed through water with-
out lofing its fmell and inflammability. Ether
takes fire very readily when heated in the
open air, or brought into contact with an in-
flamed fubftance. The electric fpark likewife
fets it on fire. Its flame is very luminous,
and leaves a black coaly mark on fubflances
expofed to it. M. Lavoifier has proved,
that cretaceous acid is formed during the
combuftion of this liquor ; and Mr. Scheele
found that the refidue of ether burned on a
fmall quantity of water, contains vitriolic
acid.

Ether difTolves in ten parts of water, ac-
cording to the Count de Lauraguais. The
phenomena produced by adding to ether all
the faline fubflances, have not yet been exa-
mined ; little more being known, than that the
action of fome acids, lime, and fixed alkalis,
do not appear capable of changing it. The
cauflic volatile alkali mixes with it in all
proportions, and forms a fluid, whofe odour
may be very ufeful in fpafmodic diforders.

Vol. IV. L * Oil

l62 ETHER.

Oil of vitriol becomes much heated by mix-
ture with ether, and converts a considerable
part of it into fweet oil of wine by diftilla-
tion. The fuming nitrous acid excites a con-
fiderable effervefcence ; the ether appearing
to become more confiftent, oily, and of a
deeper colour in this experiment. Ether has
not been combined with the other faline fub-
ftances, nor even with the inflammable mi-
neral fubftances. It is afcertained, that
ether diffolves eflential oils and refins, like
fpirit of wine ; and etherial tinftures are ac-
cordingly ufed in medicine.

Ether is confidered as a powerful tonic,
and anti-fpafmodic remedy. It is ufed in
hyfteric diforders, and fpafmodic cholics,
and is of excellent fervice in cafes where
digeftion is ill performed on account of
weaknefs of the ftomach. It muft be ad-
miniftered, however, with prudence, be-
caufe its exceflive ufe is dangerous. It is
likewife fuccefsfully applied externally in
head-achs, burns, &c. Hoffman, who made
many experiments with the vitriolic acid,
and fpirit of wine, ufed a medicine com-
pofed of fweet oil of wine diffolved in ar-
dent fpirit, which he called his mineral
anodyne liquor. The Faculty of Medicine at
Paris have added ether to this liquor, and pre-
fcribe it to be prepared by mixing two ounces
of the fpirit of wine which paffes in diftilla-
tion before the ether, two ounces of ether,

and

ETHER* l6j

and twelve drops of fweet oil of wine. This
medicine is employed for the fame purpofes
as ether, but is far from having the fame
efficacy.

The nitrous acid acts very ftrongly on
fpirit of wine. M. Navier is the firft who de^
lcribed an eafy and cheap method of prepar-
ing nitrous ether. He directs twelve ounces
of very pure and well reclined fpirit of wine
to be poured into a very ftrong glafs bottle,
and plunged in cold water, or which is ftill
better, in pounded ice : to this is to be added,
in feveral portions, the liquor being agitated
each time, eight ounces of fpirit of nitre ;
after which the bottle muft be clofed with
a good cork, covered with leather, and well
fecured. This mixture is then to be left in a
remote or private place, to prevent accidents
that might arife from the burfting of the bot-
tle, which fometimes happens. After fome
hours, bubbles arife from the bottom of
the veifel, and are gradually collected at the
top, forming a ftratum of true ether. This
difengagement continues from four to fix
days. As foon as the liquor appears to be at
reft, the cork muft be pierced with an in-
ftrument, that a certain quantity of air may
efcape, which, without this precaution*
would rufh out on opening the bottle, and
carry the ether with it. As foon as the air
is diffipated, the bottle is to be uncorked, and
the fluid it contains poured into a funnel,
L 2 whofe

164 ETHER.

whofe lower aperture being flopped with the
finger, the reiidue may be feparated from
the ether which floats above, and mud be
kept in a feparate veffel.

Mr. Woulfe defcribes another procefs for
preparing nitrous ether. It confifts in uf-
ing very large veffels, that the difengaged air
may have a confiderable fpace to expand
itfelf in. A matrafs of white glafs, con-
taining eight or ten pints, and terminated by
a neck of feven or eight feet long, is placed
on a tripod fufRciently high to admit of a
chafing-difh being put underneath. To the
neck of this matrafs, a tubulated head is
adjufted, with a tube of feven or eight
feet long adapted to its beak. The lower
extremity of the tube is received in a veffel
with two necks, whofe lower part is drawn
out into a tube, which is inferted in a bottle.
To the other neck of this receiver is adapt-
ed the apparatus of bottles, which we have
frequently mentioned as the invention of
Mr. Woulfe. Thefe veffels being well luted
together, one pound of rectified fpirit of
wine, with an equal quantity of fuming
fpirit of nitre are poured into the matrafs,
through the perforation in the head ; this
perforation is then clofed with a ground
ftopper wrapped round with a piece of lea-
ther. As foon as the mixture is made, it
becomes ftrongly heated, vapours are difen-
gaged, which pafs rapidly along the neck of

the

ETHER. 165

the matrafs, and by applying a fufficient
degree of heat to make the mixture boil,
nitrous ether paffes into the receiver. This
procefs, though very ingenious, has its in-
conveniencies. The adjuftment of the ap-
paratus is difficult, and the veffels are very
expenfive; beiides which, the method is
dangerous ; becaufe, notwithflanding the
fpace afforded to the vapours, they are dif-
engaged with ib much rapidity, that the
veffels frequently fly in pieces.

Mr. Bogues, in the year 1773, publifhed
another procefs for making nitrous ether.
He directs one pound of fpirit of wine to be
mixed with one pound of nitrous acid,
weakened fo as to exhibit only twenty-four de-
grees ofBeaume's hydrometer, in a glafs retort,
containing eight pints ; to this a receiver of
twelve pints is to be adapted, the air is
fuffered to efcape by adjufling the barrels of
two quills at the juncture of the lute, and
the diftillation muff be performed by a very
gentle heat. By this means he obtained fix
ounces of nitrous ether, of confiderable pu-
rity. It appears, from the account of the
Abbe Rozier, that Mr. Mitouard, as early
as the year 1770, ufed a procefs nearly fimi-
lar to that of Mr. Bogues. This chemift
expofed four ounces of fuming fpirit of
nitre with twelve ounces of fpirit of wine
to diftillation in a retort, which he placed
L 3 lightly

l66 ETHER.

lightly on the fand, and by this method,
which appears the moil fimple of any, he
obtained nitrous ether. Laftly, Mr. De la
Planche, apothecary at Paris, has invented
two methods of preparing nitrous ether very
conveniently. The firft confifts in putting
nitre into a tubulated (tone-ware retort, to
which a large receiver, with an adopter, is
fitted ; oil of vitriol is firft poured to the
nitre through the tube, and afterwards fpirit
of wine. The vitriolic acid difengages the
fpirit of nitre, which re-acts on the fpirit
of wine, and forms nitrous ether, almoft
immediately. As it might be fufpedted
that the ether prepared in this way was
partly vitriolic, he has fubftituted inftead
of this method, another, which is very
ingenious. An adopter, and a receiver,
which communicates, by a recurved tube,
with an empty bottle, are affixed to a tubu-
lated glafs retort, containing fix pounds of
very dry nitre. The laft veffel, namely the bot-
tle, communicates by means of a fyphon, with
another bottle, containing three pounds of
the pureft fpirit of wine. The whole being
well luted, and the retort placed on a bath
of afhes, three pounds of very pure oil of
vitriol is poured on the nitre through the
tube, which is immediately clofed with a
ground /topper. The mixture is then heated
to ebullition, and kept in that ftate till no
more vapours pafs over. In this experiment,

the

ETHER. 167

the vitriolic acid difengages the acid of nitre,
which pafles partly into the receiver, and
partly into the fecond bottle. When the
operation is ended, the receiver contains
fuming fpirit of nitre, the retort vitriolated
tartar, and the fecond bottle an etherial
liquor. This laft is diftilled in a retort
with a receiver, in the ufual method, no
more than two-thirds of the liquid being
brought over. The product is again diftilled
with a fifth part of fuming fpirit of nitre,
poured in by a little at a time, through a glafs
funnel with a long neck; two-thirds of this
liquid being likewife diftilled over. Laftly,
the fecond product is rectified by diftillation
from fait of tartar > the firft four ounces
being kept apart, and three-fourths of the
remainder fuffered to come over. The four
ounces are very pure nitrous ether ; the
three- fourths of the remainder are a nitrous
mineral anodyne liquor. The reiidues of
the two rectifications are dulcified fpirit of
nitre.

Nitrous ether obtained by thefe procef-
fes, is a yellowifh fluid, as volatile and eva-
porable as vitriolic ether, whofe fmell it
refembles, though it is .ftronger, and not
fo agreeable ; its tafte likewife is hotter, and
more pungent than that of vitriolic ether.
It contains a fmall portion of fuperabundant
acid. A large quantity of air is continually
difengaged from it, which caufes the ftoppers
L 4 of

l68 ETHER.

of the bottles containing it to fly out fre-
quently. Its flame is brighter, and the
fmoke it emits when burned, is denfer than
that of the vitriolic ether; it leaves a larger
coaly refidue; and laftly, like the vitriolic
ether, it takes gold from its folutions, and
fufpends a certain quantity.

The refidue of nitrous ether is of a lemon
yellow colour, its fmell is acid and aromatic,
and its tafte is penetrating, and refcmbles
that of diftilled vinegar. It affords, by
diftillation, according to Baume, a clear
liquor of a milder tafte than that of nitrous
ether, being an agreeable acid, which red-
dens fyrop of violets, unites with water
in all proportions, and effervefces with
cretaceous vegetable alkali. The retort
contains a yellow friable matter, of the
appearance of amber, which attracts the
humidity of the air, becomes of a pitchy
confiftence, and is foluble in water without
rendering it mucilaginous. This, which
Mr. Baume calls a gummy faponaceous fub-
ftance, if the diftillation be continued, affords
a few drops of a very clear acidulous fluid, of
an oily confiftence, and flightly empyreuma-
tic fmell. A fpungy, brilliant, taftelefs, very
fixed coal remains. Bucquet affirms, that if
the liquor which remains after the formation
of nitrous ether be evaporated, it aflumes
the confiftence of a mucilage, and at the
end of a certain time, affords faline cryftals

refembling

ETHER. 169

refembling hairy caterpillars, which have
been called cryftals of Hiaerne, from the
name of the chemift who firit defcribed
them. It has fince been difcovered, that
this relidue is the acid of fugar, which
proves that the combuftible bafe of that
acid is contained in fpirit of wine.

The muriatic acid does not fenfibly act
on fpirit of wine; this acid being only dulci-
fied by fimple mixture with the fpirit, as are
likewife the two others when mixed with a
large proportion of fpirit. Mr. Baume, in his
diflertation on ether, aflerts, that he obtained
a fmall quantity of marine ether, by caufing
fpirit of fait and fpirit of wine to meet in
the form of vapour. Ludolf and Pott ufed
butter of antimony with the fame inten-
tion. Baron Born directs the folution- of
flowers of zink in the marine acid, and
diftillation of this fait concentrated by eva-
poration in clofe veflels, with fpirit of wine.
This procefs affords marine ether, with
coniiderable facility. But no one has pur-
fued this inquiry with fo much diligence
and fuccefs as the Marquis de Courtanvaux.
According to the procefs of this chemift, a
pint of fpirit of wine is to be mixed in a retort
with two pounds and a half of the fmoking li-
quor of Libavius; a ftrong heat is excited, and
a white fuffocating vapour arifes, which dis-
appears when the mixture is agitated ; an agree-
able fmell is then perceived, and the mixture

affumes

170

ETHER

aflumes a lemon colour. The retort is to be
placed on a hot fand bath, two receivers being
luted on, the outer of which is plunged in
cold water. A dephlegmated fpirit of wine
firft paifes over, and afterwards the ether
rifes, which may be perceived by its fmell,
and the ftriae it forms in the neck of the
retort. As foon as the fmell changes, and
becomes ftrong and fuffocating, the receiver
muft be changed ; a clear acid liquor then
comes over, on the top of which float a
few drops of fweet oil. This is fucceeded
by a yellow butyraceous matter, or true
butter of tin ; and laftly, a brown ponderous
liquor, which emits abundance of white
vapours. A grey pulverulent matter, or calx
of tin, remains in the retort. The etherial
product being poured on oil of tartar in a
retort, a ftrong effervefcence takes place,
and an abundant precipitate is thrown down,
which is produced by the tin that came over
in the diftillation. A fmall quantity of water
is then added, and a fecond diftillation is per-
formed by a gentle heat ; the firft half of the
product being etherial. All the fluids, which
pafs after the muriatic ether, are loaded with
tin ; they attract the humidity of the air, and
unite with water, without affording any preci-
pitate. It was formerly very difficult to deter-
mine thecaufeof the ftrong action of themuri-
atic acid contained in the fuming liquor on fpi-
rit of wine, fince the pure acid does not at all

ad;

ETHER, I7I

act on that inflammable fluid. But, fince
the difcovery of Mr. Scheele, it appears to
be owing to the dephlogifticated or aerated
ftate of the acid ; and that its property of
converting fpirit of wine into ether mufr. be
attributed to the excefs of the bale of air it
contains. This theory was firft explained
by me in the year 1 78 1 , and is now confirmed
by the experiments of Me firs. Berthollet
and Pelletier.

M. de la Planche, the apothecary, has pro-
pofed to make muriatic ether, by pouring oil
of vitriol and fpirit of wine on decrepitated
marine fait, in a tubulated retort. The
muriatic acid gas difengaged by the vitriolic
acid, meets the vapour of fpirit of wine in
the receiver, and combines with it. An
etherial acid is produced, which may be
purified by a fecond diftillation from fixed
alkali. In this procefs, the muriatic acid
appears to take a portion of the oxyginous
principle from the vitriolic acid.

Muriatic ether is very tranfparent ; its
fmell is nearly the fame as that of vitriolic
ether; it likewife burns in the fame manner,
and affords a fimilar fmoke. But it differs
in two properties ; the one, that when
burning it exhales an odour as penetrating
as the fulphureous acid ; the other, that its
tafte is ftyptic like that of alum. Thefe
two phenomena fhew, that this ether is
different, and perhaps lefs perfect than the

two

172 ARDENT SPIRIT.

two foregoing ; and there is no doubt but
when its other properties fhall be examined,
other differences, equally remarkable, will
be obferved.

After having thus treated of the action
of three mineral acids on fpirit of wine, we
fhall refume the hiftory of this fluid. The
action of other acids on ardent fpirit has
been little examined. It is only known,
that it readily unites with the acid of borax,
or fedative fait, which communicates a green
colour to its flame ; and that it abforbs
more than its bulk of cretaceous acid. As
to the neutral falts, Macquer has determined,
that vitriolic falts are notdiflblved in thismen-
ftruum but with difficulty; that the nitrous
and the muriatic falts unite with it much
more readily ; and that in general it diffolves
faline fubftances with more facility in pro-
portion as their acid is lefs adherent. Spirit
of wine boiled on the vitriols of pot-am
and of foda, diffblved no part. Cretaceous
vegetable alkali and foda do not unite with
it, but moft ammoniacal falts do. Deli-
quefcent earthy falts, fuch as the combina-
tions of lime and magnefia, either with the
nitrous or marine acid, are perfectly diffolved.
Some metallic falts are likewife very foluble,
fuch as martial vitriol in the ftate of mother
water, cupreous nitre, the muriates of iron
and of copper, and corrofive fublimate; all

the

ARDENT SPIRIT. I73

the cupreous falts communicate a beautiful
green colour to its flame. Mr. De Morveau
has, fince the time of Macquer, given a very
accurate table of the degrees of folubility of
falts by ardent fpirit. This table is inferted
in the Journal de Phyfique.

Spirit of wine does not diffolve fulphur
either when in mafles, or in powder; but
thefe two bodies unite v/hen they meet in
the vaporous form, as the Count de Laura-
guais has difcovered. His procefs conlifts in
putting flowers of fulphur into a glafs
cucurbit, upon which flowers he places a
fmaller veflel, filled with fpirit of wine. A
head and receiver being adapted, and the ap-
paratus being heated by a fand bath, both
fubftances rifing together, combine and form
a fluid, which pafies into the receiver rather
in a turbid ftate, and emits a fetid fmell.
It contains about one grain of fulphur in the
drachm of fpirit of wine. I have difcovered
that the fame combination may be obtained
by diftilling hepatic waters, fuch as thofe of
Enghien, with fpirit of wine.

Ardent fpirit has no a&ion either on
metallic fubftances, or their calces. It partly
diflblves certain bitumens, fuch as amber
and ambergris. It does not ad: on thofe
which are black and coaly. It has been
obferved, that fpirit of wine diftilled from
fixed alkalis, a£ts more ftrongly on thefe
bitumens, and that a mixture of alkali with

thefe

174 ARDENT SPIRIT*

thefe renders them more foluble ; doubtlefs,
by converting them into a kind of foap.

There are few vegetable matters on which
fpirit of wine does not act more or lefs.
Extracts lofe their colouring part, and when
they are of the refino-extractive, or extracto-
refinous kind, great part is diffolved. Sac-
charine and faponaceous juices alfo unite
with this fluid. Margraaf, by means of
ardent fpirit, obtained a faccharine effential
fait from beet root, fkirwort, parfnips, &c.
But the matters with which it combines the
moil: readily, are the effential oils, fpiritus
rector, camphor, balfams, and refios. The
name of fpirituous diftilled waters is given to
fpirit of wine impregnated with the fpiritus
rector of plants. Thefe fluids are obtained
by diftillation from odoriferous plants v/ith
fpirit of wine. The fpirit feizes the principle
of fmell, and rifes with it, carrying up at
the fame time a certain quantity of effential
oil, which caufes it to become white by
the addition of diftilled water ; but this
principle may be feparated by rectification
on a water-bath, with a very gentle heat,
care being taken to draw off no more than
three-fourths of the fpirit, in order to be
certain of having only the fpiritus rector.
Thefe fpirituous diftilled waters acquire a
more agreeable fmell by keeping; the odorous
principle appearing to combine more inti-
mately with the fpirit.

The

ARDENT SPIRIT. I75

TheYpiritus rector has fo ftrong an affinity
with fpirits of wine, that this fluid takes it
from effential oils and water. In fact, when
fpirit of wine is diftilled from effential oils, or
from water charged with the fmell of a plant,
it takes the odorous principle, and leaves
the oil or water without fmell. It is
obferved, that fpirit of wine diffolves the
ponderous and thick effential oils more
perfectly than thofe which are fluid and
light. Water feparates this compound by
precipitating the oil in the form of white
opake globules ; but the fpiritus rector
remains united to the fpirit of wine. Spirit
of wine readily diflblves camphor in the
cold, but it diffolves a larger quantity by
the affiftance of heat. This folution, when
well faturated, as for example, two drachms
of camphor to one ounce of fpirit of wine,
being diluted with water, added drop by
drop, affords a cryftalline vegetation obferved
by Mr. Romieu. It confiils of a perpendi-
cular Item, into which fibres are inferted,
forming an angle of 60 degrees with the
perpendicular ftem. This experiment fel-
dom fucceeds, and requires many trials to
afcertain the quantity of water, the degree
of cooling, &c.

The names of tinctures, elixirs, balfams,
quintefcences, &c. are given to compounds
of oily or relinous juices in fpirit of wine,
which is fufficiently charged to have a high

colour,

I76 ARDENT SPIRIT.

colour, and to afford an abundant precipitate
by water. Like diftilled water, they are
diftinguifhed by the denomination of fimple,
when they contain but one fubftance in
folution ; or compound, when they contain
many. Thefe medicines are, in general,
prepared by expofing the dry vegetable itfelf,
whofe eflential oil or refin is required to be
extracted, or the pulverized extract of the
plant, to the action of fpirit of wine, which
is aflifted either by agitation, or the heat of
the fun, or a fand bath. When the refins
of a number of plants, or vegetable fub-
ftances, are required to be diffolved in the
fame fpirit, care mull be taken to digeft that
fubftance firft, which is the moft difficultly
acted on by the fpirit ; and to add the other
fubftances in the order of their folubility.
When the menftruum has exhaufted its ac-
tion, and is faturated, it is to be ftrained off.
A compound tincture is fometimes extem-
poraneoufly made, by mixing feveral fimple
tinctures. Thus the elixir proprietatis is
made, by mixing the tinctures of myrrh,
faffron, and aloes. Refins and balfams
may be feparated from fpirit of wine by the
affufion of water, or by diftillation ; but in
either cafe, the fpirit retains the odorous
principle.

Water is not capable of decompofing
tin&ures formed with the extracto-refmous,
or refmo-extractive fubftances, fuch as the

tincture

ARDENT SPIRIT. » ■ I77

tin&ure of rhubarb, faffron, opium, gum
ammoniac, &c. ; becaufe thefe fubftances
are equally foluble in both menftrua.

Spirit of wine and brandy are of the mofl
exteniive afe : the latter is drank with the
intention of recruiting the animal' forces ;
but it is dangerous if exceffively ufed, becaufe
it dries the fibres, and produces tremblings,
palfies, obftructions, dropfies, and other
diforders. Spirit of wine, either pure, or
with the addition of camphor, is ufed to
ftop the progrefs of gangrenes.

Spirituous diftilled waters are adminiftered
in medicine, as tonic, cordial, antifpifmodic,
ftomachic, 6cc. They are given either diluted
in water, or foftened by the addition of
fyrup.

The drinks called ratafias, or cordials, are
made with thefe diftilled waters and fugar.
When they are well prepared, and taken in
fmall quantities, they may be ufeful ; but
in general, they can be of fervice only to
few, and may produce bad confequences to
moft who take them. The exceflive ufe of
this kind of liquors is truly dangerous,
for inftead of ftrengthening the ftomach,
they in general produce the contrary effect.
Thofe which are the leaft pernicious, when
occafionally taken with moderation, may
be prepared without heat, by infufing the
aromatic fubftance in one part of rectified

Vol. IV. M fpirit

178 TARTAR.

fpirit of wine, with two parts water, and
one of fine fugar.

Tinctures have nearly the fame virtues as
the fpirituousdiftilled waters, but their action
is much ftronger ; for which reafon they are
ufed in fmall doles in pills, or with wine,
or water. The precipitates they form in
this laft cafe, are fufpended for a fufficient
time in the mixture, and the odorous part
remains diffolved in the fpirit of the tincture.

Laflly, fpirit of wine united to copal, oil
of afpic, or of the greater lavender, or to oil
of turpentine, forms varnifhes which are
called drying ; becaufe, when applied on
any fubftance, the fpirit of wine evaporates,
and leaves a tranfparent refinous coating.
A mixture of effential oil prevents thefe
varnifhes from drying too quickly, and
communicates a degree of uncluoiity, which
renders them lefs brittle.

CHAP. XXIL

Concerning Tartar.

ARTAR is an effential fait, united to
a portion of vegetable fixed alkali and
oil. It is depofited on the fides of cafks
during the infennble fermentation of wine.

It

T

TARTAR. I79

It is not produced by the fpirituous fermen-
tation, as fome chemifts have fuppofed ; for
Roueile the younger difcovered it ready
formed in unfermented wine, or muft, and
in verjuice.

It has the form of irregular plates, difpofed
in ftrata, often full of brilliant cryftals, and
of a vinous acid tafte. It is diftinguifhed
into white tartar, and red tartar, the latter
differing from the former only in a greater
abundance of colouring matter. "

Crude tartar expofed to heat in clofe veffels,
affords a reddifh acid phlegm, an oil at firft
light, and afterwards ponderous, coloured,
andempyreumatic j a fmall quantity of vola-
tile alkali, and much cretaceous acid, which
Hales, Boerhaave, and many other che-
mifts fuppofed to be air. A coal remains,
which contains a large quantity of creta-
ceous vegetable alkali, and is ealily burned.
Vegetable alkali, of confiderable purity, is
obtained by the combuftion and incineration
of tartar.

With this intention, pulverized tartar is
wrapped up in papers, which are afterwards
dipped in water ; thefe are ranged in a fur-
nace, between two ftrata of charcoal, which
being fet on fire, the tartar burns, and is
calcined ; when the fire is burnt out, the
papers of tartar are found in their original
form ; theie are lixiviated with cold diftilled
water, which after filtration is evaporated
M 2 to

l8o TARTAR.

to a pellicle, and fuffercd to cool, in order
to feparate the vitriolated tartar, which cryf-
tallizes by repofe. The fluid folution be-
ing decanted off, is evaporated and cryftal-
lized a fecond time ; and this procefs is re-
peated as long as any cryftals are afforded :
after which it is evaporated to drynefs, and
affords vegetable alkali, partly cauftic, and
partly combined with cretaceous acid.

Tartar is but fparingly foluble in water :
one ounce of that fluid, at the temperature of
55 degrees of Fahrenheit, diffolved no more
than four grains. As it contains a large quan-
tity of oleaginous colouring matter, it is pu-
rified by folution and cryftallization, at Ani-
ane and CalviiTon, in the neighbourhood of
Montpellier. Dr. Fizes has given a full de-
fcription of this purification, in a memoir
printed among thofe of the Academy in 1725.

The tartar is boiled in water, and filtered
while hot ; the folution becomes turbid on
cooling, and depofits irregular cryftals, which
form a parte ; the pafte is boiled in copper
veffels, together with water, mixed with an
argillaceous earth, brought from Merviel, two
leagues from Montpellier. A ,fcum rifes to
the top, which is carefully taken off, and is
at length fucceeded by a faline pellicle. The
fire is then put out ; and the pellicle being
broken, falls to the bottom, among the cryf-
tak which precipitated from the folution.
The earth, which fouls thefe cryftals, is

wafhed

TARTAR. l8l

wafhed off with cold water, and they are
then fold, under the name of cream of tar-
tar, or cryftals of tartar ; which differ only
ID the circumftance, that the cream is formed
at the furface, while the cryftals are depofited
at the bottom of the liquor. The white clay
appears to deprive the tartar of its fuper-
abundant oily and extractive matter.

Tartar according to M. Defmaretz, is,
purified in a fomewhat different manner at
Venice. The pulverized fait, being diffolved
in boiling water, depoiits its impurities,
from which it is carefully feparated, and the
liquor affords cryftals by cooling. Thefe
cryftals are re-diffolved in water, gradually
heated ; and as foon as it boils, beaten whites
of eggs, with fifted wood afhes, are thrown,
in. This mixture of allies is made fourteen
or fifteen times ; the fcum is taken off, and
the liquor left to cool. A pellicle of very
white faline cryftals is foon formed, which
after the water is decanted, are fuffered to
dry. This method changes the nature of
the cream of tartar, by converting a part
into tartarized vegetable alkali. We fhall
proceed to examine the chemical properties
of cream of tartar, or tartar purified in the
neighbourhood of Montpellier.

Very pure cream of tartar is. cryftallized,
though irregularly; it has an acid tafte, lefs vi-
nous than that of crude tartar. On hot coals,
it emits much fmoke, of a penetrating empy-
M 7 reumatic

j82 TARTAR.

reumatic fmell, and itfelf becomes black and
carbonaceous. If cream of tartar be diftilled
in an earthen retort, with a receiver, connected
with an inverted veffel of water, by means
of a tube, and the fire be gradually raifed, a
phlegm, almoft colourlefs, and fcarcely acid,
firft comes over ; next a ftronger acid, of a
deeper colour; and afterwards an oil, which
becomes more and more coloured, confiftent,
and empyreumatic ; and laft of all, the
concrete volatile alkali, and a large quantity
of cretaceous acid. A very abundant coal
remains in the retort, which, lixiviated with-
out incineration, affords a large quantity of
fixed alkali. The diftilled products may be
rectified by a gentle heat. In this rectifica-
tion, the phlegm partes over nearly colour-
lefs, the oil becomes very white and volatile,
the volatile alkali partly combines with the
acid, and is not obtained feparate and pure,
but by diftilling the laft portions of phlegm
with the addition of fixed alkali. The ve-
getable fixed alkali, contained in the coal, is
not produced in the operation, as many che-
mifts have thought, but is all contained ori-
ginally in the tartar. The re-action of the
fixed alkali on the oil produces the volatile
alkali; and the quantity of volatile fait may
be increafed, by diftilling the oil obtained
from the cream of tartar a fecond time, with
the coal it leaves in the retort.

Cream

TARTAR. 183

Cream of tartar is not altered by expofure
to air.

It diffblves in twenty-eight parts of boil-
ing water, and cryftallizes confufedly by
cooling, as we have obferved. A certain
quantity of earth feparates from the folutioa
of this fait, which is doubtlefs that which
was ufed in its purification : the folution
reddens tincture of turnfole, and has an acid
tafte.

The action of quartzofe earth, clay, and
ponderous earth, or barytes, on cream of
tartar, is not known. The chemifts of the
academy of Dijon have obferved, that mag-
neiia forms, with cream of tartar, a foluble
fait, decompofable by fixed alkali, and af-
fording, by evaporation in the open air, fmall
prifmatic cryftals in radii. This tartar of
magnefia boils up, and becomes converted
into a light coal, by expofure to the action
of fire. M. Poulletier de la Salle obtained
from this combination a gelatinous mafs,
perfectly refembling mucilage.

The action of lime, and of chalk, on cream
of tartar, has been well defcribed by feveral
chemifts. When chalk is thrown into a fo-
lution of cream of tartar, an effervefcence is
produced, occafioned by the difengagement
of cretaceous acid ; and a very abundant pre-
cipitate, conlifting of a combination of the
tartareous acid and lime, is formed. The
fupernatant liquor contains a neutral fait,
M 4 which

184 TARTAR.

which exifted, ready formed, in the cream
of tartar, and confifts of the acid of tartar,
united to vegetable alkali: it is known, as
we fh'all prefently fee, by the name of fo-
luble tartar. We are indebted to Rouelle
the younger for this valuable analyfis of
cream of tartar -y which proves, 1 . That
this fubftance is compofed of a fuperabun-
dant oily acid, and a certain quantity of this
acid, united to vegetable fixed alkali, in the
ftate of a neutral fait. 2. That the combi-
nation of the tartareous acid with lime, forms
a neutral fait of very difficult folubility. Mr.
Prouft has difcovered, that calcareous tartar,
diftilled in a retort, leaves a refidue, which
takes fire by expofure to air, like pyropho-
rus. Bergman, in his difTertation on the
elective affinities, gives a procefs for fepa-
rating the the tartareous acid. He directs
the precipitate formed by chalk thrown into
a folution of cream of tartar, to be warned
with diftilled water j this tartarized lime
being then put into a phial, eight times its
weight of vitriolic acid, confiding of one
part of oil of vitriol, and eight water, muft
be poured thereon. After digefting for twelve
hours, and being frequently ftirred with
a fpatula of wood, the clear liquor muft be
decanted off from the mixture ; the de-
poiition at the bottom muft likewife be
wafhed with water, till it no longer com-
municates any tafte ; and the water ufed in

wafhing

TARTAR, 185

wafliing is to be added to the former liquid.
This is the tartareous acid. It is evident,
in this experiment, that the vitriolic acid
decompofes the calcareous tartar, and forms
felenite, at the fame time that it diiengages
the tartareous acid, which remains diiTolved
in the water. The acid thus obtained al-
moft always contains a fmall quantity of vi-
triolic acid, which may be precipitated by
the addition of a fmall quantity of calcareous
tartar, the earth falling. down with the vi-
triolic acid, in the form of felenite, while
the tartareous acid is difengaged. Bergman
adds, that the folution of this acid, evapo-
rated to the confidence of fyrup, affords
cryftals, in plates or fcales ; that thefe cryf-
tals become black by heat, and afford, by
diftillation, an acidulous phlegm, with a
fmall quantity of oil ; leaving a reiidual coal,
which is neither acid nor alkaline. Hence
it appears, that the tartareous acid contains
oil, like all the other acids of vegetables.

Cream of tartar unites very well with the
different alkalis. If it be added to a 'folu-
tion of cretaceous vegetable alkali, a ftrong
effervefcence is immediately produced, by
the difengagement of the cretaceous acid.
The cream of tartar rnuft be added to fatu-
ration, and the liquor filtered, after hav-
ing boiled for half an hour ; after which,
the evaporation being continued till a pellicle
is formed, the folution, by flowly cooling,

affords

l86 TARTAR.

affords long quadrangular prifms, terminated
by two facets, placed flantwife. This fait
is known by the names of vegetable fait,
foluble tartar, tartarized tartar, and ought to
be called tartar of pot-afh. It has a bitter
tafte ; is converted into a coal by a ftrong
heat ; and is decompofed by diftillation, af-
fording an acid phlegm, oil, and a large quan-
tity of cretaceous acid. It flightly attracts
the humidity of the air, and is completely
diffolved in four parts of water, at the heat
of 120 degrees. The mineral acids decom-
pofe it, and precipitate cream of tartar ; it
is alfo decompofed by mod metallic folu-
tions.

Cream of tartar, combined with foda,
forms fait of Seignette, fo called from the
name of an apothecary of Rochelle, who flrfl
compofed it. It is prepared, by diffolving
twenty ounces of cream of tartar in four
pounds of water, and gradually adding very
pure cryftallized vegetable alkali tofaturation,
which point is known by an effervefcence not
being excited by the addition of more alkali.
In this combination the cream of tartar is
rendered more foluble. The fluid being
evaporated, till it has nearly the confidence
of fyrup, affords, by cooling, very beauti-
ful regular cryftals, often of a confiderable
magnitude. They are prifms of fix, eight,
or ten unequal faces, truncated at right
angles at their extremities. Thefe prifms
are moft commonly bifedted length wife j and

the

'tartar. 187

the large face, or bafe, on which they reft,
is marked by two diagonal lines, interfer-
ing each other, and dividing the bafe into
four triangles. The fait of Seignette, which
ought to be called tartar of foda, was at firft
fold as a fecret, but was difcovered, at the
fame time, by Boulduc and Geoffroy, in
1731. It has a bitter tafte ; is decompofed
by the fire, like the tartar of pot-afh ; efflo-
refces in the air, becaufe it contains much
water of cryftallization, and is nearly as
foluble as tartar of pot-afh, and, like that
fait, is decompofed by mineral acids and
metallic folutions. The mother water of
this fait, contains the portion of tartar of
pot-afh, which compofes part of the cream
of tartar.

The volatile alkali forms, with cream of
tartar, an ammoniacal tartareous fait, which
crystallizes very well by evaporation and
cooling. Bucquet affirms, that its cryftals
are rhomboidal pyramids. Macquer obferved
fome, in thick prifms, of four, five, or fix
fides ; others thickeft in the middle, and
terminated by very acute points. The aca-
demicians of Dijon obtained them in ob-
lique angled parallelopipedons. Ammoni-
acal tartar has a cool tafte, and is decom-
pofed by heat : in the air it efHorefces : hot
water diffolves it more readily than cold ; and
\t cryftallizes by cooling. Lime and fixed

alkalis

1 88 TARTAR.

alkalis difengage the volatile alkali ; mineral
acids and metallic folutions decompofe it.

Pott and Margraaf treated cream of tartar
with the mineral acids, and the latter ob-
tained neutral falts, fimilar to thofe afforded
by each of thefe acids with vegetable alkali ;
whence he concluded, that this alkali exifts,
ready formed, in cream of tartar. Rouelle
the younger made a number of accurate ex-
periments, which afforded the fame refults.
A pound of cream of tartar, in very fine
powder, was added to a pound of oil of vi-
triol ; the mixture became hot, and the
mutual adtion of the two fubftances on each
other was affifted by the heat of a water-
bath, and by frequent ftirring with a glafs
inftrument. This heat being continued ten
or twelve hours, the mixture became of the
thicknefs of cream, at which period two or
three ounces of boiling diftilled water were
added, which rendered the whole fluid.
Two hours after, the mixture was taken
from the fire, and three pints of boiling dif-
tilled water were added. This folution was
coloured, and opake, and contained difen-
gaged vitriolic acid, a portion of cream of
tartar not decompofed, and vitriol of pot-afh.
The excefs of vitriolic acid was then fatu-
rated with chalk $ and felenite, with a fmall
quantity of cream of tartar, were precipitated.
The mixture was then filtered and evaporated,
till it became reduced to eighteen or twenty

ounces $

TARTAR. 189

ounces ; during which, a fmall quantity of
cream of tartar and of felenite, fell down. The
fluid was decanted off, evaporated a fecond
time, and by ftanding afforded vitriolated tar-
tar; more of which was obtained in the like
manner by fucceffive evaporations. This
fait is always mixed with a fmall quantity of
cream of tartar, and burns on a hot iron.
But if a due quantity of diftilled water be
added, the vitriolated tartar will be taken
up, and the cream of tartar will remain un-
diiTolved. The foregoing procefs is defcribed
by Berniard, who repeated it with fuccefs
after Rouelle.

The nitrous and muriatic acids, treated in
the fame manner with cream of tartar, afford
nitre and febrifuge fait ; which incontro-
vertibly proves the exiftence of vegetable al-
kali in this fubftance.

Cream of tartar acquires folubility, by
uniting with borax and fedative fait. Ac-
cording to the experiments of M. De Laf-
fone, one part of the latter fait may render
about four parts of cream of tartar foluble.
This mixed folution affords a greenifh, very
acid gummy fait, by evaporation.

Cream of tartar appears capable of uniting
with moft metallic fubftances, as Meffrs.
Monnet and the chemifts of the academy of
Dijon have fhewn. But as thefe combina-
tions have been little examined, we fhall
only fpeak, in this place, of thofe of anti-
mony,

I90 TARTAR.

mony, mercury, lead, and iron; becaufe
they are better known, and are moil of them
ufed in medicine.

The combination of cream of tartar and
antimony, is called ftibiated, or antimoniated
tartar, or more commonly emetic tartar. As it
is one of the moft important remedies afforded
by chemiftry, it is neceffary to examine its
properties with the greateft care. Since the
time of Adrian de Mynficht, who firft de-
fcribed this compofition, in the year 1631,
the procefs for making it has been greatly
varied. The Pharmacopeia, and the writings
of chemifts, all differ, either in the antimo-
nial fubftances directed to be employed, as
well as in the cream of tartar and water,
either with refped: to quantity, or the me-
thod of applying them to each other. Berg-
man, in his differtation on this medicine,*
has given an excellent fedtion on the diffe-
rent proceffes heretofore ufed in preparing
antimoniated tartar. The crocus metallo-
rum, the liver, the glafs, and the flowers of
antimony, have been fucceffively prefcribed :
fome diredt thefe fubrtances to be boiled
with cream of tartar, and a greater or lefs
quantity of water, for ten or twelve hours ;
others direct the ebullition to be continued
no longer than half an hour; others again
require the filtrated lixivium to be evaporated

* E%s, Vol. I.

to

TARTAR. I9I

to drynefs ; and laftly, there are others who
direct it to be cryftallized, and the cryftals
only to be ufed in medicine. Hence it hap-
pens, that antimoniated tartar is never the
fame fubftance, but pofieffes various de-
grees of force, fo that its effects cannot be
clearly afcertained. And accordingly Geof-
froy, who examined many fpecimens of an-
timoniated tartar, of different degrees of
force, found, by the analyfis, that the weak-
eft contained from thirty to ninety grains of
regulus, in the French ounce of 576 grains.
Thofe of a middle degree of emetic power,
1 08 grains, and the ftrongeft 1 54 grains. Glafs
antimony has been chofen in preference to
other antimonial fubftances, becaufe it is
one of the moft foluble by cream of tartar ;
but this glafs may be more or lefs calcined,
and the different degrees of calcination muft
affect its emetic power. However, if very
tranfparent glafs of antimony, previoufly well
levigated, be boiled in water, with an equal
weight of cream of tartar, till the latter is fa-
turated, and this folution be filtered and
evaporated by a gentle heat, cryftals of an-
timoniated tartar are obtained, by Hand-
ing, whole emetic power appears to be
fufficiently conftant. The liquor being
decanted and evaporated, affords new cryf-
tals for feveral fucceflive times. The mother
water contains fulphur, tartar of pot-am,
and a certain quantity of liver of fulphur.
When the mixture of cream of tartar, glafs

of

I92 TARTAR.

of antimony, and water, which has been
boiled for the preparation of antimoniated
tartar, is paffed through the filtre, a yellow
or brown gelatinous fubflance remains be-
hind, which Rouelle has examined, and finds
to afford, by diftillation, a very inflammable
pyrophorus.

Macquer propofes to fubftitute the powder
of algaroth, inftead of glafs of antimony, in
the preparation of emetic tartar ; becaufe this
powder is itfelf a violent emetic, and when
precipitated from the butter of antimony is
always the fame. Bergman has adopted the
opinion of Macquer; and fince that time,
emetic tartar has been prepared in the labo-
ratory of the academy of Dijon according to
the method of Bergman and M. De Laffone.
This medicine has been ufed with the greateft
fuccefs : it operates, in a dofe of three grains,
without fatiguing the ftomach or interlines.
Antimoniated tartar cryftallizes in very
tranfparent trihedral pyramids, decompof-
able by heat, which converts them to a
coaly fubflance. It efHorefces in the air,
and becomes a white farinaceous powder ;
it is foluble in fixty parts of cold water,
or in a much lefs quantity of hot wa-
ter. It cryftallizes by cooling ; and is de-
compofed by lime and alkalis. Calcareous
earth, and pure water, in, a large dofe, are
capable of decompofing it ; whence it fol-
lows, that it ought to be adminiftered only
in diftilled water. Liver of fulphur, and

hepatic

TARTAR. I93

hepatic gas, precipitate from it a red pow-
der, or kind of golden fulphur, which may
ferve as a tefl for the prefence of this fait in
all liquors containing it. Iron feizes the
acid of tartar, and feparates the calx of anti-
mony ; antimoniated tartar ought not, there-
fore, to be prepared in verTels of this metal,
Mr. Durande, phyficianand profeffor at Dijon,
propofes that this medicine be made publick-
ly, and by one uniform procefs, eflablifhed
by law, as the theriaca is made ; and we are
convinced, that the greateft advantages would
arife to the pra&ice of phyfick from fuch a
regulation being adopted.

The tartareous acid may be combined with
mercury by two methods. The one mention-
ed by Mr. Monnet, confifls in diffolving fix
parts of cream of tartar in boiling water, with
one part of mercury, precipitated from the
nitrous acid by cretaceous vegetable alkali.
This liquor, filtered and evaporated, affords
cryftals, that are decompofable by pure wa-
ter. The fecond method of uniting mer-
cury with the tartareous acid, conlifts in
pouring a nitrous folution of this metal into
a folution of tartar of pot-afh, or tartar of
foda : a precipitate of mercurial tartar is af-
forded, and the nitre of pot-afh, or foda, re-
mains diffolved in the liquor.

Cream of tartar has a fenfible action oh
the calces of lead. Rouelle the younger has
afcertained, that the faturnine tartar, pro-

Vol. IV. N duced

194 TARTAR,

duced in this operation, does not remain
dlffolved, but that the liquor, by evapora-
tion, affords pure vegetable alkali, which
was ready formed in the cream of tartar.
This is one of the proceffes he has made ufe
of to prove that fixed alkali exifts in tartar.

Copper, and its calces, are readily attacked
by the tartareous acid : the refult is a fait, of
a beautiful green, capable of cryftallization,
but hitherto little examined.

Iron is very ftrongly acted on by cream of
tartar. A medicine, called chalybeated tar-
tar, is prepared, by boiling eleven ounces of
levigated iron filings with one pound of
white tartar, in twelve pounds of water.
When the tartar is diflblved, the liquor is
filtered, and depofits cryftals, more of which
may be obtained by fubfequent evaporation.
To prepare the tartarized tincture of Mars,
a pafte is made, with fix ounces of iron fil-
ings, one pound of white tartar in powder,
and a fufficient quantity of water. This
mixture is left at reft for twenty-four hours ;
after which twelve pounds of water are add-
ed, and the whole boiled for two hours;
frefh water being added in proportion as the
evaporation goes forward. The liquor is then
decanted, filtered, and thickened, by boiling
to the coniiftence of fyrup ; after which one
ounce of fpirit of wine is added. Rouelle
afcertained, that the fixed vegetable alkali
exifts at liberty in this tincture, and that by

heating

TARTAR. I95

heating it with acids, neutral falts, with
bafe of this alkali, are obtained. There are
likewife two other medical preparations,
formed by the combination of the tartareous
acid and iron. The one is foluble martial
tartar, confifting of one pound of the tarta-
rized tincture of Mars, and four ounces of
tartar of pot-a(h, evaporated to drynefs. The
other is known by the name of martial balls.
They are made by mixing, in a glafs veifel,
one part of fteel filings, and two parts of
white tartar in powder, with a certain quan-
tity of brandy ; when the brandy is evapo-
rated, the mafs is pulverized, and more
brandy added, which is fuffered to evaporate
as before. This procefs is repeated till the
mafs becomes tenacious, when it is formed
into balls.

Crude tartar is very ufeful in the art of dy-
ing, and it is likewife made ufe of by hat-
makers.

The different preparations of cream of tartar
which we have enumerated, are moftly ufed in
medicine ; pure cream of tartar is confidered
as cooling and antifeptic. In the dofe of
half an ounce, or an ounce, it purges gently,
and without exciting naufea. The tartars
of pot-afh and of foda are often ufed, in
conjunction with other purgative medicines,
in the dofe of a few drachms : antimoniated
tartar is one of the moft ufeful and effica-
cious medicines afforded by chemiftry. Th;.
fait is emetic, purgative, diuretic, diapho-

N 2 retic

I96 TARTAR.

retic, or deobftruent, according to the dofes
and proceffes ufed in adminiftering it. It
often produces all thefe effects at one time.
It may alfo beconfidered as a powerful alter-
ative, of excellent ufe in removing obftruc-
tions of the vifcera, when given in fmall
dofes often repeated. It is adminiftered as
an emetic, in the dofe of from one to four
grains, diffolved in water. It is mixed, in
the dofe of a grain, with other purgatives,
whofe action it affifts : and laftly, when
given in the quantity of half a grain, greatly
diluted with water, it acts as an alterative.
M. De LafTone has difcovered, that antimo-
niated tartar is rendered very foluble in wa-
ter by the mixture of fal ammoniac ; and
that a mixed fait, fimilar to fal alemrSroth,
is produced. It may be concluded, that
this new compound is capable of producing
confiderable effects on the animal economy.
Chalybeated tartar, foluble martial tartar,
and the tartarized tincture of Mars, are ufed
as tonic and aperient medicines.

CHAP.

ACID FERMENTATION. I97

CHAP. XXIII.

Of the Acid Fermentation, and of Vinegar,

M

ANY vegetable fubftances, fuch as
gums and amylaceous fecula, diffolved
in boiling water, are capable of undergoing
the acid fermentation ; but this property is
more efpecially remarkable in fermented and
fpirituous liquors. All thefe fluids, when ex-
pofed to heat in contact with air, undergo the.
acid fermentation, and afford the liquor called
vinegar. The wine of grapes is more efpe-
cially ufed in preparing this liquor, though
it is poffible to make very good vinegar with
cyder, perry, &c*

There are three conditions neceffary to the
acetous fermentation: 1. A degree of heat from
750 to 900 of Fahrenheit. 2. A fubftance at
the fame time vifcous and acid, fuch as muci-
lage and tartar. 3. The con tad: of air. The
change which wine undergoes, when it be-
comes converted into vinegar, muft be attri-
buted to an inteftine motion, excited in the
fluids by the prefence of a certain quantity of

* Vinegar is made in Britain from wort, which is the
infufion of malt, made in the fame way as in the procefs
of brewing. T.

N 3 mucilage

I98 ACID FERMENTATION.

mucilage, which is not changed, and is capa-
ble of paffing through a new fermentation.
The prefence of an acid fubftance, fuch as
tartar, is neceffary to determine the acid fer-
mentation. Laftly, the contadt of air is in-
difputably neceffary, and it appears that a
certain portion is abforbed during this fer-
mentation, as the Abbe Rozier has proved.

All wines are capable of forming vine-
gar. The bad wines are employed in pre-
ference, lor the fake of cheapnefs ; but the
experiments of Beccher and Cartheufer,
prove, that generous wines, abounding with
ardent fpirit, afford in general the beft vine-
gar.

Boerhaave, in his Elements of Chemiftry,
has defcribed a very good procefs for making
vinegar. Two large cafks are provided, and
a falfe bottom of wicker is fixed, at fome
diftance from the bottom, within each, on
which vine branches and grape ftalks are
fpread : wine is then poured in; fo that one
of the veffels is filled, and the other only half
full. The fermentation commences in the
latter : when it is well eftablifhed, it i3 fill-
ed up with wine added from the other tun.
By this means, the fermentation is retarded
in the full veffel, and accelerated in the
other. When it has arrived at a confiderable
degree in this laft, it is again filled up, by
transferring part of the fluid from the other;
the fermentation confequently recommences

ia

ACID FERMENTATION, I99

in the veflel from which the liquor was lafl
taken, and becomes flower in that which is
filled up. The alternate rilling and empty-
ing of the veflels is continued till the vine-
gar is perfectly formed, which ufually hap-
pens in twelve or fifteen days.

When the effects of this fermentation are
attend to, much ebullition and hifling is per-
ceived ; the liquor becomes hot and turbid,
exhibits a great quantity of filaments and
bubbles, agitated in every direction ; a ftrong
acid fmell, not at all dangerous, is emitted,
and a large quantity of air is abforbed. It
is neceffary to impede the fermentation every
twelve hours. Thefe phenomena gradu-
ally become lefs, the heat decreafes, the
motion decays, and the fluid recovers its
tranfparency : a fediment is depofited, in
reddifh flocks, which adhere to the fides
of the veflels. Numerous experiments
have fhewn, that the fmaller the quan-
tity of wine, and the more perfed: the ac-
cefs of air, fo much the more readily does it
pafs to the flate of vinegar. The vinegar muft
be carefully drawn off, in order to feparate it
from its lees, which, without this precau-
tion, would quickly caufe it to undergo the
putrid fermentation. Vinegar does not de-
pofit tartar by flanding, like wine ; this fait
is diflblved, and combined with the ardent
fpirit and water during the fermentation. It is
N 4 even

200 ACETOUS ACID.

even probable, that the prefence of this fait
contributes to the tafte and other acid pro-
perties of vinegar. This fluid has more or
lefs of colour, according to that of the wine
ufed in its preparation ; but in general, vi-
negars, which have the leaft colour, are far
from being of as light a colour as the white
wines, becaufe they hold in folution the
colouring matter of the tartar, which has
likewife been developed by the production
of the acid.

Vinegar, prepared in the method here de-
fcribed, is very fluid -y of an acid and fpiri-
tuous fmell ; and of a four tafte, of different
degrees offtrength: it reddens blue vegetable
colours. When expofed to a warm tempe-
rature, in imperfectly clofed veffels, it be-
comes changed, lofing its fpirituous part,
and depofiting a great quantity of mucilagi-
nous flocks and filaments, at the fame time
that it affumes a putrid fmell and tafte. In
order to preferve it, it is neceflary to boil it
for a fhort tim£, as Scheele has obferved.*

When vinegar is diftilled by a naked fire,
in an earthen alembic, or in a glafs retort,
on a fand-bath, a phlegm, of a lively and
agreeable fmell, but fcarcely acid, firft paffes
over -, this is fucceeded by a very white and
odorous liquor, called diftilled vinegar. The
following products have lefs fmell, and more
acidity, as the diftillation advances. If thefe

* This difcovery, announced in Scheele's EfTays, p. 315,
Englifti tranilation3 did not fucceed with me upon trial. T.

pro*

ACETOUS ACID. 201

products be taken feparately, diftilled vine-
gars, differing from each other in acidity and
fmell, may be obtained; but it is ufual, in
this procefs, to draw off about two-thirds of
the liquor, which conftitutes the pureft vi-
negar. The portion which comes over af-
terwards is more acid, but it has an empy-
reumatic fmell, which may be diffipated by
expofure to air ; it is likewife flightly co-
loured. This operation {hews, that the
acetous acid is lefs volatile than water. The
remaining vinegar is thick, of a deep and
dirty colour, depofits a certain quantity of
tartar, and is considerably acid. If it be
evaporated in open veffels, it takes the form
of an extraft; and if, when dried, it be dif-
tilled in a retort, it affords a reddifh phlegm,
acid, an oil at firft light coloured and after-
wards heavy, with a fmall quantity of vola-
tile alkali. The remaining coal contains
much fixed alkali.

Vinegar may be concentrated by expoling
it to froft. The frozen part con lifts almoft
intirely of water; the part which remains
fluid, being decanted off, is found to be
much more acid : the quantity of vinegar
thtfs obtained is fmall.

The acid of vinegar, feparated from tartar
and the colouring matter, by diftillation, is
capable of uniting with a great number of
bodies.

It does not readily combine with argilla-
ceous earth, with which it forms cryftals,

in

202 ACETOUS ACID.

in fmall needles, whofe properties are little
known. It is the acetous fait of clay.

This acid unites readily with magnefia,
and affords a fait, which is very foluble in
water, and does not afford cryftals, but is
converted into a vifcous deliquefcent mafs,
by evaporation. The acetous fait of mag-
nefia is decompoied by fire, by the mineral
acids, by ponderous earth, by lime, and by
the alkalis. It is very foluble in fpirit of
wine.

The acid of vinegar combines with lime,
and decompofes chalk, whofe acid it difen-
gages, in the form of an elaftic fluid. The
fait it forms with lime, cryftallizes in very
fmall prifms, of a fattin appearance. The
calcareous acetous fait is bitter, and four,
and effiorefces in the air. Fire decompofes
It j its earth is feparated by fixed alkalis;
and the mineral acids difengage its acid.

The combination of the acid of vinegar
with vegetable alkali, is called terra foliata
tartari, and ought to be called, the acetous
fait of pot-afh. This fait is prepared, by pour-
ing very pure diftilled vinegar on white fait of
tartar •> the mixture is agitated, and the vi-
negar added, till the faturation is perfecl,
and the fait well diffolved. It is proper to
add an excefs of acid. The liquor, being firft
filtered, is evaporated, by a gentle heat, in a
veiTel of porcelain, or pure filver j and when
it becomes thick, the evaporation is conti-
nued

ACETOUS ACID. 203

nued to drynefs, on a water-bath. By this
means, a very white terra foliata is obtained.
If too ftrong a degree of heat be ufed, it
becomes grey, or brown, by the burning of a
portion of the vinegar. Some chemiiis affirm,
that this fait may be obtained in a regular
form, by cooling the folution prcvioufly eva-
porated to a thick pellicle. The acetous fait
of pot-afh has a penetrating, acid, and uri-
nous tafte. It is decompofed by the action
of fire; and affords, by diftillation in a re-
tort, an acid phlegm, empyreumatic oil,
volatile alkali, and a large quantity of ftrong-
fmelling gas, conlifting of a mixture of cre-
taceous and inflammable gas. The refidua!
charcoal contains much difengaged fixed al-
kali. This fait ftrongly attracts the humi-
dity of the air, and is very foluble in water.
The vitriolic acid decompofes it. For this
purpofe, one part of oil of vitriol is poured
on two parts of the acetous fait of pot-am,
introduced into a tubulated retort, to which
a receiver is adapted : a vaporous fluid, of a
penetrating fmell, is immediately difengaged,
with a ftrong effervefcence, which condenfes
in the receiver, into a liquor called radical
vinegar. This vinegar is very concentrated,
and ftrongly acid j but it is not pure, as it
always contains a certain quantity of ful-
phureous acid, diftinguilhable by its fmell.
Cream of tartar likewife decompofes the ace-
tous fait of pot-afh, becaufe it has a ftronger

affinity

204 ACETOUS ACID.

affinity than the acetous acid with the alka-
line bafe of this fait.

Vinegar unites perfectly with foda, and
forms a fait, improperly called cryftallizable
terra foliata. This does not differ from the
acetous fait of pot-afh, but in its cryftalliz-
ing in ftriated prifms, refembling thofe of
the vitriol of foda, and in its not attracting
the humidity of the air. To obtain perfect
cryftals, the folution muft be evaporated to
a pellicle, and fet in a cool place. The
acetous fait of foda is decompofed by fire,
and the mineral acids -, and we may obferve,
that if the calcareous, or alkaline acetous
falts, be diftilled by a ftrong heat, the re-
lidues are pyrophori, which take fire when
expofed to the air. Mr. Prouft, the dif-
coverer of thefe facts, is of opinion, that a
pyrophorus is produced in all cafes, where a
carbonaceous refidue is divided by an earth
or a metallic calx.

The acid of vinegar, with the volatile al-
kali, forms a liquor, known by the name of
fpirit of Mindererus. This fait is fo vola-
tile, that it cannot be evaporated without
lofing the greateft part of it. Neverthelefs,
cryftals, in the form of needles, and of a
hot and penetrating tafte, may be obtained by
flow evaporation. The ammoniacal acetous
fait is decompofed by the action of fire, by
lime and fixed alkalis, which difengage the

volatile

ACETOUS ACID. 205

volatile alkali, and by the mineral acids,
feparate the vinegar.

Vinegar ads on almoft all metallic fub~
jftances, and its combinations are attended
with a variety of important phenomena.

It does not appear to diflblve the calx of
arfenic ; but this laft fubftance diftilled with
an equal part of the acetous fait of pot-afh,
afforded Meffrs. Cadet, and the chemifls of
the Academy of Dijon, a red fuming liquor
of a naufeous fmell, very tenacious, and of
a Angular nature. Mr. Cadet had before
obferved, that this liquor inflames fat lute.
The academicians of Dijon being defirous
of examining a yellowifh matter of an oily
confidence, collected at the bottom of the
veffel, which contained the arfenico-acetous,
fuming liquor, decanted a portion of this
fuperfluent liquor, and poured the reft on a
filter of paper. A few drops had fcarcely
parTed, when immediately an offenfive and
very thick fume arofe, which formed a
column from the veffel to the cieling ; a
kind of ebullition was excited on the borders
of the matter, and a beautiful rofe-coloured
flame iflued forth ; all which lafted a few
feconds. A full account of the experiments
of thefe learned Academicians, may be feen
in the third volume of the Elements of
Chemiftry of Dijon. They compared the
liquor we have fpoken of to a liquid phof-
phorus; we think it is a pyrophorus of

the

206 ACETOUS ACID.

the fame kind as thofe we (hall prefer* tly
mention. The refidue of the diflillation of
the acetous fait of pot-afh with calx of
arfenic, confills for the moft part of vegetable
fixed alkali.

Vinegar dhTolves the calx of cobalt, and
forms a folution of a pale rofe colour. t

It has no aclion on bifmuth, or its calces.

It diflblves nickel direclly, according to
Mr. Arvidfon ; this folution affords green
cryftals, of the form of a fpatula.

The acetous acid does not appear to ad:
on the regulus of antimony, but it appears
to diffolve the glafs of this femi-metal; iince
Angelus Sala made an emetic preparation
with thefe two fubftances.

Zink, and alfo its calces, are readily
diifolved by vinegar. Mr. Monnet obtained
cryftals from this folution in the form of
flat plates. The acetous fait of zink fulmi-
nates on hot coals with a blueifh flame. By
diflillation it affords an inflammable liquor,
a yellowifh oily fluid, which foon becomes
of a deep green ; and a white fublimate,
which when fet on fire by a candle, burns
with a beautiful blue flame -, the refidue is
in the ftate of a pyrophorus, not very com-
buftible.

The acid of vinegar does not diffolve
mercury in its metallic ftate ; but this
combination may be made by dividing the
mercury into very fmall particles, as was

done

ACETOUS ACID. 207

done by Keyfer. Mercury, in the ftate of
calx, readily unites with vinegar. The acid
may be boiled either on precipitate per fe,
on turbith mineral, or mercury precipitated
from its nitrous folution by the vegetable
alkali. The fluid becomes white, but recovers
its tranfparency when boiling hot; it is then
to be filtered, and filver-coloured cryflals
fall down, in fcales refembling fedative fait.
This has been called mercurial foliated earth,
or mercurial acetous fait. It may be immedi-
ately prepared by pouring a nitrous folution
of mercury into an acetous folution of vege-
table alkali ; the nitrous acid unites with
the fixed alkali of this laft fait, and forms
nitre, which remains diffolved ; while the
calx of mercury, combining with the acid
of the vinegar, is precipitated in the form
of brilliant fcales. The mixture being then
filtered, the mercurial acetous fait will re-
main on the filter. This fait is decompofed
by the action of fire, and its refidue affords
a kind of pyrophorus. It is quickly altered
by combuftible vapours.

Tin is not much altered by vinegar. This
acid diffolves only a fmall quantity of that
metal, which by folution afforded Mr. Mon-
net a yellowifh fubftance refembling gum,
and of a fetid fmell.

The acid of vinegar acts more ftrongly
on lead than on moft other metals, and
diffolves it with the utmoft facility. When
thin plates of this metal are expofed to

the

208 ACETOUS ACID.

the vapour of heated vinegar, they become
covered with a white powder called cerufe,
which is a calx of lead. Cerufe ground
with one third part of chalk, forms the
white lead ufed as a paint. In order to
faturate vinegar with lead, the acid is poured
on cerufe in a matrafs ; the mixture is fet
to digeft on a fand bath, and after feveral
hours is evaporated to a pellicle ; by cooling
it affords white cryftals, forming either irre-
gular needles, if the fluid has been too much
concentrated ; or flat parallelipipedons, ter-
minated by two flant fe&ions, when the
evaporation has been well made. This is
called fait or fugar of Saturn, on account
of its fweet tafte, which is at the fame time
very ftyptic. A fait of the fame nature is
made, by boiling equal parts of litharge and
of vinegar, and evaporating it to the con-
fiftence of fyrup. This is the extradt of
Saturn of Mr. Goulard, which long before
his time was known by the name of vinegar
of Saturn. Salt of Saturn, or the acetous
fait of lead, is decompofed by heat ; it
affords an acid, ruddy, and very fetid liquor,
different from radical vinegar. The reiidue
is a very good pyrophorus. This fait * is
decompofed by diftilled water, by lime, by
alkalis, and by the mineral acids. The
extract of Saturn, diluted with water, and
mixed with a fmall quantity of brandy,
forms the vegeto-mineral water.

Vinegar

ACETOUS ACID. 209

Vinegar quickly diffolves iron ; the effer-
vefcence which takes place in this folution
arifes from the difengagement of inflammable
gas afforded by the water, which feems to
be decompofed. The liquor has a red or
brown colour ; and by evaporation affords
only a gelatinous magma, together with
fome long brown cryftals. The Martial
acetous fait has a ftypric and fweetifh tafte ;
is decompofed by fire, which drives off its
acid ; attracts the moifture of the air, and
is decompofed in diftilled water. When
heated till it no longer emits a fmell of
vinegar, it leaves a yellowifh calx attracted
by the load-ftone. The acetous folution of
iron affords a very black ink with nut-galls,
and may be fuccefsfully ufed in dying. The
phlogifticated alkali precipitates a very bright
Pruffian blue. Martial cethiops, the pre-
cipitates of iron, the faffrons of Mars, the
fparry iron ore, afford folutions with vine-
gar of a very fine red colour.

Diftilled vinegar diffolves copper with
very great facility, and by the affiftance of
heat it gradually affumes a green colour. But
the acid acts more readily on this metal
when already calcined by vinegar, and con-
verted into the fubftance called verdigris.
Verdigris is prepared in the neighbourhood
of Montpellier, by plates of copper in earthen
veffels, covered in layers with the hufks of
grapes, which have been previoufly fprinkled

Vol. IV. O and

210 ACETOUS ACID.

and fermented with weak vinegar. The
furface of theie plates foon become covered
with a green ruft, which is increafed by
piling them together, and fprinkling them
with weak vinegar. The copper is then
fcraped, and the verdigris is packed in
facks of leather for fale. M. Monnet,
apothecary at Montpellier, has very well
defcribed this procefs, in two Memoirs
printed among thofe of the Academy of
Sciences, for the years 1750, and 1753.
Verdigris readily diffolves in vinegar, and
the folution, which is of a beautiful green
colour, affords by evaporation and cooling,
green cryftals, in truncated quadrangular
pyramids, called cryftals of Venus. The
cryftals prepared for commerce, which are
called diftilled verdigris, becaufe diftilled
vinegar is ufed in preparing them, have the
figure of a pyramid ; its cryftals affume
this form, becauie they are depofited on
a ftick cleft into four branches, which are
kept afunder by a piece of cork.

The acetous fait of copper has a ftrong
tafte, and is a violent poiibn. It is decom-
pofed by the action of fire, efflorefces in
the air, and becomes covered with a powder,
whole green colour is much paler than that
of the fait itfelf. It is completely diflblved
in water without decompolition. Lime-
water and alkalis precipitate the calx of
copper.

When

ACETOUS ACID. 211

When this fait is pulverized and diftilled
in an earthen or glafs retort, a fluid is ob-
tained at firft pale and fcarcely acid ; but
affords afterwards one fo ftrong, as to refemble
the mineral acids. The receiver muft be
changed during the operation, in order that
the phlegm and the acid may be had feparate ;
the latter is called radical vinegar. It has
a green colour, arifing from a certain quan-
tity of the calx of copper which comes over.
When the diftillation ceafes, and the bot-
tom of the retort is red hot, the refidue is
a brown copper coloured powder, which
often communicates a metallic tinge to the
fides of the veffel. This refidue is ftrongly
pyrophoric, as the Due D'Ayen and Prouft
have obferved. Radical vinegar is rectified
by diftillation with a gentle heat ; it is then
perfectly colourlefs, provided the heat has
not been urged too ftrongly, fo as to dry
the remaining calx of copper. The reduc-
tion of the copper referved in this experi-
ment explains the nature of radical vinegar.
This acid appears to have the fame relation
to common vinegar, as the aerated or oxy-
ginated muriatic acid has to the pure muri-
atic acid. In this operation the acetous acid
unites with the oxyginous principle of the
calx of copper, which at the fame time
refumes the metallic ftate. The rery dif-
ferent effe&s produced by radical vinegar,
compared with thofe of the common acetous
O 2 acid,

212 ACETOUS ACID.

acid, appear therefore to arife from its excels
of the oxyginous principle.

Radical vinegar, thus rectified, has fo
ftrong and penetrating a fmell, that it is
impoifible to fupport it for any length of
time ; its caufticity is fuch, that it corrodes
and burns the fkin, and it is extremely
volatile and inflammable. When heated
with contact of air, the rapidity with which
it burns is the greater, the more highly it is
rectified. This experiment has induced
chemifts to believe, that vinegar is an acid
combined with an ardent fpirit ; it may,
perhaps, be confidered as a kind of natural
ether. This notion is rendered probable,
by the penetrating and agreeable fmell emit-
ted by the firft portions of this acid in
diftillation. Radical vinegar evaporates in-
tirely, when expofed to the air ; it unites
to water, with much heat ; with earths,
alkalis, and metals, it forms the fame falts
as common vinegar ; but its action on com-
buftible bodies is in general much more
rapid. The Marquis de Courtanvaux has
fhewn, that it is only the laft portion of
the acetous fluid obtained by diitillation
from cryftals of verdigris which is inflam-
mable 5 and that it likewife has the property
of being congealed by cold. This lait por-
tion when rectified, ciyftallized in the re-
ceiver in large plates and needles, and did
not become fluid, at a leis heat than about 62

degrees

ACETOUS ACID. 213

degrees of Fahrenheit. In this property like-
wife it refembles the aerated muriatic acid.

The acid of vinegar, affifted by heat,
diflblves the precipitate of gold made from
aqua regia by adding a fixed alkali. This fo-
lution, precipitated by volatile alkali, affords
fulminating gold, as Bergman has (hewn.
Vinegar does not aft on platina or filver,
while they are in the metallic ftate, but it dif-
folves their calces.

This acid combines with many of the
immediate principles of vegetables. It dif-
folves extracts, mucilages, and effential falts ;
unites with the fpiritus reftor, and is con-
iidered as the proper folvent of gum refins.
It has even after a certain length of time in.
the way of diftillation, a confiderable action
on fat oils, which it converts into a fapo-
naceous ftate. But the combination of vi-
negar with vegetable fubftances, has been
by no means accurately examined.

This acid is ufed to extrad: fame of the
vegetable principles, more eipecially that of
fmell; and vinegars of different nature, either
fimple or compound, are prepared for medical
ufe. The vinegars of fquills, colchicum,
&c. afford an example of the firft ; the the-
riacal vinegar, and the vinegar of the four
thieves, are of the fecond kind, Thefe me-
dicines are prepared by maceration and di-
geftion continued for feveral days. As the
^cid is volatile, it is diftiUed from aromatic
O 3 plants,

214 ACETOUS ACID.

plants, whofe odorant principle it takes up j
the diftilled vinegar of lavender ufed as a
perfume is of this kind -, thefe liquors are
in general lefs agreeable than fpirituous dif-
tilled waters.

Radical vinegar decompofes fpirit of wine,
and forms ether with the fame facility as
the mineral acids, as the Count de Laura-
guais has difcovered. For this purpofe, ra-*
dical vinegar is poured on an equal quantity
of fpirits of wine in a retort. A confiderable
degree of heat is excited. The retort is
then placed in a fand bath, with two receivers
fitted on, the outer being plunged in cold
water or pounded ice. The mixture being
quickly brought to ebullition, adephlegmat-
ed fpirit of wine paries firft, afterwards the
ether, and laftly an acid which is ftronger
as the diftillation advances : a brown mafs,
confiderably refembling a refin remains in
the retort. Care muft be taken to change
the receiver as foon as the etherial fmell
becomes fharp and penetrating, that the acid
may be collected apart from the ether. The
ether muft be rectified by a gentle heat with
alkali. A large proportion is loft in this ope-
ration. The formation of the acetous ether is
owing to theexcefs of the oxyginous principle
in radical vinegar. Mr. Scheele affirms, that
he did not fucceed in preparing acetous
ether, by adding radical vinegar to fpirit of
wine, and that he did not obtain it, but by
the addition of a mineral acid, Mr. Pcer-

ner

ACETOUS ACID. 215

ncr had before made the fame remark con-
cerning the difficulty of obtaining acetous
ether by the procefs of Mr. de Lauraguais.
However, many French chemifts have exe-
cuted that procefs ; and I can myfelf affirm,
that I have repeated it with fuccefs.

M. de la Planche, the apothecary, prepares
acetous ether, by pouring oil of vitriol and
fpirit of wine on fait of Saturn, introduced
into a retort. The theory and practice of
this operation, are abfolutely the fame as
thofe of the nitrous and muriatic ethers,
prepared by a like procefs.

The acetous ether has an agreeable fmell
like other ethers, but it always partakes
of the fmell of vinegar, though it is not
acid. It is very volatile and inflammable,
burns with a bright flame, and leaves a coaly
mark after its combuftion.

Vinegar is much ufed as to feafon food.
It is likewife of excellent ufe in medicine,
as a refrefhing and antifeptic fluid. A fyrup
is made with fugar, which is given with
great fuccefs in burning or putrid fev:rs,
&c. ; this acid, externally applied, is aftrin-
gent and bracing. All its combinations are
likewife applied to medical ufes.

The acetous falts of vegetable and mineral

alkali, which are known by the names of

terra foliata tartari, and mineral acetous fait,

are powerful deobftruent and aperient re-

O 4 medies ;

2l6 ACETOUS ACID.

medies ; they are adminiftered in the dofc
of from half a drachm to a drachm.

The fpirit of Mindererus, or folution of
ammoniacal acetous fait, taken in the dofe
of a few drops in a proper liquid, is aperient,
dieuretic, cordial, antifeptic, &c. It often
fucceeds in the leucophlegmatia, or fvvelling
of the external parts of the body.

The Mercurial acetous fait, or Mercurial
terra foliata, is an excellent anti-venereal;
it is the principal ingredient in Keyfer's
pills.

The extract of Saturn, vinegar of Saturn,
and the vegeto-mineral water are applied
externally as deficcatives. Thefe medicines,
being ftrongly repellent, ought to be admi-
niftered with great caution, efpecially when
applied to parts which are ulcerated or with-
out fldn. Boerhaave mentions feveral young
women attacked with confumptions, in con-
fequence of the external ufe of preparations
of lead.

Cerufe enters into the compofition of
drying unguents and plafters, and verdi-
gris is a component part of feveral collyria
and unguents.

Radical vinegar is ufed as a very powerful
ftimulant to be refpired by fuch as fall into
fainting fits. For the convenient ufe of this
remedy, a certain quantity is poured on vi-
triolated tartar grofsly powdered, which is
kept in a well clofed bottle j this medicine

k

PUTRID FERMENTATION. 217

is univerfally known by the name of fait of
vinegar.

Acetous ether has not yet been applied to
any ufe; neither is it known whether it has
any peculiar virtues, differing from thofe of
the other ethers.

CHAP. XXIV.

Concerning the Putrid Fermentation of
Vegetables.

ALL the vegetable fubftances, which
**** have paiTed the fpirituous and acid fer-
mentation, are fufceptible of a third intef-
tine commotion, by which they are changed;
this is called the putrid fermentation. Stahl,
and feveral other chemifts, have thought,
that this kind of fermentation is merely a
confequence of the two preceding, or rather
that thefe three phenomena depend on a
fingle procefs, or motion, which tends to
deftroy the texture of folid fubftances, and
to change the properties of fluids. It is true,
in fact, that if certain vegetable fubftances
be left to themfelves, they pafs through the
three fermentations fucceffively, and without
interruption. For example; all faccharine
matters, diffolved in a certain quantity of

water,

2l8 PUTRID

water, and expofed to a degree of heat of
about 60 or 80 degrees, afford, firft wine,
afterwards vinegar, and at laft the acid cha-
racter is deftroyed ; they patrify, lofe all
their volatile principles, and become dry,
infipid, and earthy. But it mult be ob-
ferved, that a great number of vegetable fub-
ftances do not pafs through thefe three kinds
of fermentation, at leaft as far as fenfe can
diftinguifh. Infipid mucilages, and folu-
tions of gum in water, become four, with-
out exhibiting any appearance of fpirit ; and
the glutinous matter appears to pafs imme-
diately to putrefa&ion, without previoufljr
becoming acid. It therefore appears, that
though thefe three fermentations fucceed
each other in many of the vegetable prin-
ciples, there are neverthelefs many others
which are capable of the two laft, without
the foregoing, or even of putrefying, with-
out exhibiting previous figns of acidity.
Thefe laft participate of the nature of animal
fubftances, and afford volatile alkali by the
adtion of heat, and mephitis by the nitrous
acid. It appears to 6e from this character,
that the vegeto-animal fubftances putrefy fo
readily.

The inteftine motion which changes the
nature of vegetable matters, and reduces
them to their elements, requires the follow-
ing conditions. Humidity, or the prefence
of water, is one of the mod neceffary ; dry

and

FERMENTATION. 219

and folid vegetables, fuch as wood, are not
at all changed, while they remain in that
ftate; but if they be moiftened, and their
fibres feparated, the inteftine motion foon
commences : water, therefore, appears to be
one of the caufes of putrefaction -3 and we
fhall fee, in the animal kingdom, . that the
decompofition of this liquid appears to pro-
duce fermentation. Heat is not lefs necef-
fary. Cold, or the temperature of ice, not
only oppofes this fpontaneous deftruction,
but retards its progrefs, and in fome mea-
fure reftores the former flate of fubftances
which have began to change. The degree
of heat, neceffary to putrefaction, is much
lefs than that which maintains the fpirituous
and acid fermentation, fince it requires no
more than about 45 degrees of temperature ;
but a ftronger degree of heat is more favour-
able to this procefs, provided it be not fo
ftrong as to volatilize all the humidity, and
intirely to dry the fubftance which putrefies.
Accefs of air is a circumftance which Angular-
ly promotes putrefaction, fince vegetable fub-
ftances are very well preferved in a vacuum.
This prefervation, however, has its limits ;
and the contact of air does not appear to be
indifpenfable for carrying on putrefaction,
like the two conditions before-mentioned.

The putrefaction of vegetables has its pecu-
liar phenomena. Vegetable fluids, which pu-
trefy, become turbid, lofe their colour, and

depofit

220 PUTRID

depofit different fediments ; bubbles rife fco
the furface, and mouldinefs appears at the
beginning. Vegetable matters, fimply moif-
tened, and foft, exhibit the fame pheno-
mena; the commotion is never fo great as
in the fpirituous and acetous fermentations.
The bulk of the matter which putrefies does
not appear to increafe, neither does its tem-
perature rife ; but the moft important phe-
nomenon is the change of fmell, and the vo-
latilization of an acrid penetrating urinous
principle, fimilar to the volatile alkali, and
which, on examination, is found to be that
fubflance. Hence the putrefactive fermenta-
tion has been diftinguifhed by the name of
the alkaline fermentation, and the volatile
alkali has been coniidered as its product.
The. penetrating fmell flies off by degrees,
and is fucceeded by a naufeous, faint fmell,
not ealily defcribed. The decompofition is
then at its height; the putrefying vegetable
matter is then very foft, or fluid, like a fy-
rup -, it experiences a great number of fuc-
ceflive modifications in the odorant prin-
ciple which exhales. Laftly, it dries, its
difagreeable fmell is diflipated by degrees,
and nothing remains but a blackiih, and as
it were, coaly refidue, known by the name
of earth, humus vegetabilis, in which no-
thing is found but certain faline and earthy
fubftances. Such is the order of the phe-
nomena obferved in the fpontaneous decom-
pofition

FERMENTATION* 221

pofition of vegetables which putrefy : but
this decompofition, carried to that point in
which bodies are reduced to their faline or
earthy fkeleton, requires a very long time;
and it may even be added, that it has not yet
been properly obferved by any perfon. This
reproach which is call on chemifts and philo-
fophers for their inattention to animal matters,
is much more deferved with regard to vegeta-
ble fubftances. No philofopher has yet under-
taken to obferve the complete putrefaction of
thefe laft, though many have begun todefcribe
the phenomena which take place in that of
animal matters. We may therefore conclude
the hiftory of the fpontaneous and natural
analyfis of vegetables, by adding, fimply,
i. That the fhort account we have given
fhews, that vegetable putrefaction attenuates,
volatilizes, and deftroys their humours, and
reduces them to the earthy ftate. 2. That
nothing is yet certainly known concern-
ing the phenomena and limits of this kind
of putrefaction, which requires to be proper-
ly diftinguiihed from that of animal matters.
3. Laftly, as this fermentation is much more
evident, and has been better obferved in the
fluids and folids of animal fubftances, the
larger detail we mall enter into, refpecting
thefe laft, will complete our hiftorical iketch
of the known fafts relating to putrefaction.

PART

( 222 )

PART IV.

■—— —————— ■ i ■

The ANIMAL KINGDOM,

CHAP. I.

The General Chara&ers of Animals.*

NIMALS are in general diftinguifhed
from vegetables, by locomobility, and
more perfed: organization. Yet, there are
intire claffes of thefe which are fixed to
a place ; fuch as the lithophytes, and zoo-
phytes, which are produced and die on the
fame fpot. And, on the other hand, certain
vegetables have as much motion in their
leaves and flowers, as certain animals ; for
example, fhell-worms. The organization

* We do not here prcpofe to exhibit more than a fketch
of the methods of naturalifts, to facilitate the progrek of
beginners in the ftudy of natural hiflory, as treated by the
beft writers : but our plan does not permit us to enter
fiilly into general confiderations on the nature of animals,
which have been treated in fo elegant and philofophical a
manner by the Count De BufTon and Mr. Bonnet. F.

even

ANIMALS. 223

even appears lefs perfect in polypi than in
moft plants. Hence it is very difficult to
draw a true line of difcrimination between
thefe two kingdoms ; and modern naturalifts
have therefore been under the neceffity of
confounding them in one fingle arrange-
ment, called the organic kingdom.

Neverthelefs, when we coniider perfect
animals, we find great differences between
them and vegetables. Numerous and dif-
tinct organs, a more complicated ftructure,
and a greater variety of functions, are the
characters in which thefe differences confift;
but it does not appear the lefs difficult to
give a good definition of thefe fubflances.

By attending to the moll: general charac-
ters, v/e may define animals to be bodies
endued with fenfation and motion, neceffary
to preferve their life. They are all capable
of re-producing their like : fome, by the
union of the two fexes, produce fmall living
creatures; others lay eggs, which require
nothing more than a due temperature, in
order to produce young. There are fome
which multiply without conjunction of fexes ;
and others which are re-produced when cut
in pieces, like the roots of plants. The
true character, or fpecific diftinction of ani-
mals, is not eafily affigned. The mixture
of races produces numberlefs varieties ; and
tranfportation into different climates occa-
fions numerous changes in the form, mag-
nitude,

224 CLASSIFICATION OF

nitude, colours, &c. of. animals. We cart
only, therefore, confider thofe as diftindt
fpecies, which have conftantly the fame form,
and are perpetuated by the re-production of
individuals ; and the alterations produced by
the intermixture of fpecies, climate, $o-
meftication, &c. conftitute the varieties.

The number of animals which cover the
furface of our globe being very confiderable,
it would be impoffible to diftinguifh them
from each other, if nature had not prefented
remarkable differences in their external fi-
gure, on which distinctions are eafily efta^
blifhed. Naturalifts have at all times been
fenfible of the utility of thefe differences,
which they have advantageoufly applied in
claffing animals into methodical diviiions.
Although it is certain, that thefe claffifica-
tions do not exift in nature, but that the
whole chain of created beings is uninter-
rupted, yet it is certain, that thefe methods
affift the memory, and are of great ufe in
the fludy of natural hiftory. We may there-
fore confider thefe methods, as instruments
appropriated to our limited powers, by the
help of which we may fuccefsfully attend to
the riches of nature. Ariftotle eftablifhed
only general and fimple diviiions -, but his
mafterly confiderations, refpefting the inte-
rior and exterior organs of animals, have
formed a bale, on which the divifions of the
firft naturalifts, iuch as Gefner, Aldrovandus,

Jonfton,

ANIMALS. 225

Jonfton, Charleton, Ray, &c. are in great
part founded. Thefe early naturalifts have
been fucceeded by a great number of others,
who have rendered the methods more per-
fect, and have added to the knowledge we
poifefs ; but among thefe laft, thofe whofe
works more particularly require to be known,
and from whom we mall borrow, are Meffrs.
Klein, Artedi, Linnaeus, Briffon, Dauben-
ton, Geoffroy.

After man, whofe organization and intel-
ligence place him at the head of animated
bodies in a feparate clafs, all ether animals
may be divided into eight claffes ; namely,
quadrupeds, cetacea, birds, viviparous quad-
rupeds, ferpents, fillies, infects and worms,
and polypi. Thefe claffes might be more
multiplied, but the difficulties would in-
creafe in the fame proportion, and defeat the
purpofe of artificial claffification, whofe fole
merit confifts in limplicity and perfpicuity.
Mr. Daubenton, who has paid great atten-
tion to the claffification of animals, has ar-
ranged them in the fame manner, and has
confidered the ftructure of the principal con-
ftituent parts of each, to (hew that the
claffes are gradually degraded, from quad-
rupeds, which neareft refemble man, to
worms, which are the mofl remote. See
Table I.

Vol. IV. P CHAP.

226 QUADRUPEDS

CHAP. II.

Concerning Quadrupeds and Cetaceous
Animals.

Zoology.

QUADRUPEDS are animals having
^^^four feet, whofe body is moft com-
monly covered with hair. They refpire by
lungs fimilar to thofe of man; and like him
they have a heart, confifting of two ventri-
cles : they are viviparous. Thefe animals
referable man the neareft in their flru&ure ;
there are even fome, as for example, the ape
and a few others, which Linnaeus has thought
proper to include in the fame order as man.
This naturalift gives the name of mammalia
to this clafs, in which he comprehends ce-
taceous fiih, becaufe they have teats, and
give milk to their young. Though this
clafs of animals appears to refemble man in
fome refped:s, yet they differ greatly from him
in feveral important particulars. Such are the
horizontal fituation of their bodies, the form
of their extremities, the thicknefs and hard-
nefs of their fkin, which is hairy, or covered
with a hard and as it were corneous fub-

ftance,

QUADRUPEDS. 12J

ftance, the prolongation of the vertebras of
the back into a tail, the anterior part of the
cranium flat and horizontal, the ears large
and long, the bones of the nofe and upper
jaw very long, and placed obliquely. When
we compare this ilru&ure to that of the
human fpecies, whofe body is perpendicular,
the bone called radius moveable, the fingers
perfectly feparate, the thumbs oppofed to
the four other fingers, and the fkin fmooth
and thin, we mail be fenlible how much
this conformation exalts its fenfibility, and
renders it fuperior to the mod perfedt of
other animals. The anatomy of its internal
parts, and the hiftory of its functions, add
iiill more force to thofe important conclu-
iions.

The ancient naturalifts, at whofe head
Ariftotle and Pliny may be placed, havS
diftinguimed quadrupeds only by the place
of their habitation. For which reafon, and
the want of accurate defcriptions, it is often
impofiible to afcertain the animals they
fpeak of. Later naturalifts, perceiving the
difadvantages of this method, adopted an-
other, which is very different; they have
availed themfelves of the moft obvious dif-
ferences on the external parts of animals, to
eflablifli charadters readily known, by the
afiiftance of which they may with certainty
be diftinguiflied from each other. We fhall
in this place explain three artificial methods

Pa of

228 QUADRUPEDS.

of claffing quadrupeds; namely, thofe of
Linnaeus, Vogel, and BrifTon.

The Method of Linnaeus.

Linnsus has divided animals with teats,
or the mammalia, in feven orders. The
firft, comprehending thofe which he calls
primates, has for its characters incifive teeth
in both jaws ; conftantly four in number in
the upper jaw ; two teats on the breads, and
the arms feparated by claviculae : this order
contains four genera -, man, homo ; the ape,
jimia-y the lemur, or profimia; and the bat,
vefpertillio. It cannot but be admitted
that this method is very remote from na-
ture, fince it arranges in the fame order,
creatures fo diffimilar as man and the bat.

Animals of the fecond order are diftin-
guifhed by the name of bruta : their cha-
racters are the want of incifive teeth, their
feet armed with ftrong hoofs, and their pace
flow. This order includes fix genera, which
•are the elephant, elephas ; the fea-cow, /r/-
checus ; the (loth, bradypus •> the ant-eater,

myrmecophaga ; the mam's ; the tato w,

da/ypus. The two firft genera are very re-
mote from the four others.

In the third order, the Swedifh naturalift
diftinguiihes favage beafts by the name of
ferae. In this he comprehends all animals
with teats, whofe incifive teeth are conical,

and

QUADRUPEDS. 229

and ufually fix in number in each jaw,
whofe canine teeth are very long grinders,
not flatted, feet armed with fharp nails, and
which tear their prey, and live by deftroy-
ing other creatures. There are ten genera
of this order ; the feal, phoca ; the dog,
cam's; the cat, fe/is ; the ferret, viverra; the
weazel, mujlela; the bear, urjhs; the opofium,
didelphis ; the mole, ta/pa ; the fhrew-moufe,
for ex ; and the hedge -hog, erinaceus.

The fourth order, intitled glires, or rats,
is diftinguifhed by the following characters :
the animals which compofe it have two in-
cifive teeth in each jaw, and no canine teeth;
their feet are armed with claws proper for
leaping ; they live on barks, roots, &c.
This order comprehends fix genera ; namely,
the porcupine, hijirix ; the hare, lepus ; the
caftor, cajior ; the rat, mus ; the fquirrel,
fciurus -, and the American bat, to which
Linnasus has given the name of nodtilio.

In the fifth order, he includes, under the
name of pecora, fuch quadrupeds as have
incifive teeth in the lower jaw, and none in
the upper ; whofe feet are cloven, and which
ruminate. The camel, camelus -> the muik
animal, mofchus-y the flag, cervus; the goat,
capra ; the fheep, ovis ; the ox, bos ; are the
fix genera which compofe this order.

The fixth order includes, under the deno-
mination of belluae, fuch quadrupeds as have
the incifive teeth obtufe, and their feet

P 3 hoofed.

23O QUADRUPEDS.

hoofed. The four genera of this order,
namely, the horfe, equus; the hippopotamus,
hippopotamus ; the hog, Jus ; and the rhino-
ceros, rhinoceros, are very well diftinguifhed
from each other by the number of then-
teeth, and the form of their feet. Laftly,
in the feventh order, which comprehends
the cetaceous animals, is diftinguifhed from
all others by the form of the feet, which
refemble fins : but as we think proper, with
many modern naturalifts, to make a peculiar
clafs of cetaceous animals, we ihall fpeak of
them after quadrupeds.

The method of Linnaeus appears to be de-
fective in many refpects ; not only in its ar-
ranging together animals fo diffimilar as man
and the bat, &c. and feparating animals fo
fimilar as the rat and the moufe, &c. but
likewife becaufe the divifions are not fuffi-
ciently numerous, and do not readily enable
us to diftinguifh each quadruped; which
laft requifite is indilpenfably neceffary, arid
is in fad: the only advantage a method is re~
quired to poffefs.

The Method of Klein.

Klein divides quadrupeds into two prin-
cipal orders : in the firft, he arranges thofe
whofe feet are ungulated, pedes ungulati Jive
cheliferi ; in the fecond, thofe whofe feet are
digitated, pedes digit at i.

The

QJJADRUPEDS. 23!

The firft order is divided into five fami-
lies, whole characters are founded on the
diviiion of their ungulated feet in feveral
pieces. The firft family, called monQchela9
comprehends the genus of the horfe : the
fecond, whofe individuals are diftinguifh-
ed by the name dicbela, includes all thofe
whofe feet are cloven into two parts, bijulci.
Some have horns, as the bull, the ram,,
the goat, the flag, &c. others are not horn-
ed, as the hog, the boar, the babyroufTa.
The trichela, or animals, whofe ungulated
feet are divided into three parts, compofe
the third family, of which the rhinoceros
is the only variety. The fourth family,
whofe character confifts in the feet being di-
vided into four pieces, tetrachela> contains
only the hippopotamus. The fifth, which
is diftinguifhed by the feet being divided
into five parts, pentachela, includes only the
elephant.

The fecond order of quadrupeds, whofe
feet are digitated, is likewife divided into five
families ; the firft comprehending animals
with two digits, didadlyla, confifts of the
camel and the filenus, or floth of Ceylon.
The fecond family, or animals of three di-
gits on their feet, trida&yla, includes the
floth and the ant-eater. The third, or te-
tradaBila, or animals of four digits, contains
tatous, or armadillos, and Guinea pigs, which
feem to be a fpecies of rabbits. The fourth

P 4 family,

232 QUADRUPEDS.

family, characterized by five digits on the
feet, pentadatlila, is the moft numerous of
all; it contains the rabbit, the fquirrel, the
dormoufe, the rat and the moufe, the opof-
fum, the mole, the bat, the weazel, the
porcupine, the dog, the wolf, the fox, the
coati, the cat, the tyger, the lion, the bear,
the ape : the number of fpecies compre-
hended under thefe genera is very confide-
rable. It muft be obferved, that in all thefe
characters, taken from the form of the
feet, Klein confiders only the fore* feet in
his diftindtion of families. Laftly, the
fifth family confifts of animals whofe feet
are irregular, anomalopedia ; fuch are the
otter, the caftor, the fea-cow, and the
feal.

The fame objection may be made to the
fyftem of Klein, as to that of Linnaeus,
Though his firft divifions are fufficiently dis-
tinctive of the families, the genera are not
fo eafily afcertained according to his method,
more efpecially thofe of the fourth family.

The Method of M. Briffon.

M. Briflbn has avoided moft of thefe in-
conveniences, by combining together all the
characters of the naturalifts who have pre-
ceded him. He has availed himfelf of the
number of teeth, or their abfence, the form
of the extremities, that of the tail, the na-
ture

CETACEOUS ANIMALS. 233

ture of the appendices, fuch as the horns, the
fcales, the prickly fpines or quills. His com-
bined method is doubtlefs the moft complete,
and beft adapted to diftinguifh any quadru-
ped, and refer it to its proper genus. We here
prefent his divilions in the form of a table;
it exhibits the characters of thefe animals to
their refpective genera, and has the advan-
tage of being very fimple, and eafily under-
ftood. See Table II.

Concerning Cetaceous Animals.

Cetaceous animals are of a large fize, in-
habit the ocean, and by the ftructure of their
lungs and blood-velfels, are capable of liv-
ing'in water, as we fhall more fully explain
in the hiftory of refpiration. They referable
quadrupeds in the ftructure of their .breafts,
and in general of all their internal organs,
as well as in their bringing forth living
young. But they differ from them in the
form of their extremities, which terminate
in fins, and in two large apertures, at the
upper part of their heads, through which
they can: up the water to various heights.
Naturalifts call thefe pafTages fpiracula.
The number of genera of thefe animals
is much lefs conliderable than that of quad-
rupeds. M. BrifTon has diftinguifhed them,
1. Into fuch as have no teeth, as the whale,

balcena*

2"34 BIRDS.

balcena. 2. Into fuch as have teeth only in
the upper jaw, as the narwal, or unicorn fifh,

monodon, vel monoceros. 3. Such as have
teeth only in the lower jaw, as the phyfeter.
4, and laftly, Such as have teeth in both
jaws, as the dolphin, delphinus.

CHAP. HI.

Concerning Birds.

Ornithology.

T>IRDS are biped animals, which move
■*-* through the air by means of wings, are
covered with feathers, and have a beak of a
horny fubftance. A great number of inte-
refting fads are obfervable with regard to
thefe animals, relative to the various form
of their beak, the ftrufture of their feathers,
the motions they perform, and their man-
ners or habits. The moll important of thefe
will be exhibited in the abridgment of phy-
fiology, which we fhall give in the fol-
lowing pages ; but at prefent we fhall only
attend to the external characters which na-
turalifts have taken to diflinguifh birds, and
clafs them methodically. The earlier writers
on this part of natural hiftory have efta-

blifhed

BIRDS. 235

blifhed no other differences between birds
than fuch as relate to the places they inha-
bit. Hence they have diftinguifhed them
into birds inhabiting woods, plains, feas,
rivers, lakes, &c. Others have diftinguiihed
them from their food, into birds of prey,
granivorous birds, &c. &c.

But the methodical writers have diflin-
guilhed birds in another way. Linnaeus has
divided them after the form of their beak
into fix orders, like the quadrupeds with
which he has compared them. But thefe
divifions do not appear fufficiently exteniive,
efpecially when we confider that the number
of fpecies in birds is much more confidera-
ble than in quadrupeds, fince M. de Buf-
fon reckons the quadrupeds at two hundred,
and the birds at fifteen hundred, or two
thoufand. We fhall therefore only mention
in this place the methods of Klein and of
Briffon.

Klein divides birds into eight families,
after the form of their feet; the firft under
the name of didaffiles, comprehends fuch as
have two digits on their feet ; the oftrich is
the only fpecies in this divifion. The fe-
cond contains the tridaffyles, fuch as the
cafuary, the buflard, the lapwing, and the
plover. The third contains the tetrada&yles,
which have two digits behind and two be-
fore ; fuch as the parokeet, the wood-pecker,
the cuckcow, and the king-fiiher. The

fourth

236 BIRDS.

fourth contains the tetrada5iylesy three of
whofe digits are before, and one behind.
This family is the moft numerous of any,
as it comprehends the birds which prey by
day and by night, fuch as the raven, the
magpye, the ftarling, the thrufh, the black-
bird, the lark, the red-breaft, the fwallow,
the titmoufe, the woodcock, &c.

The fifth family contains the tetraftyks,
whofe three anterior digits are united by a
membrane, and the pofterior at liberty.
Thefe birds are called palmipedes ; the goofe,
the duck, the fea-maw, and the diver, com-
pofe this family. The fixth includes the
tetradaftyles, whofe four digits are united
by a membrane. Thefe in latin are called
planet. The pelican, the cormorant, the
booby, and the anhinga , are arranged by
Klein in this family. The feventh is com-
pofed of fuch as have only three digits,
and thefe united by a membrane ; they are
called the tridaByles palmipedes. The guil-
lemot, the penguin, and the albatros, belong
to this family. Laftly, the eighth clafs in-
cludes the tetradaffyles, whofe digits have
membranes fringed, or as it were torn ;
thefe are alfo called da&ylobes. Coots, and
fome of the fpecies of divers, compofe this laft
family. The method of Klein, though more
comprehenfive than that of Linnaeus, is not-
withstanding attended with many difficulties
in afcertaining the genera, efpecially that

of

OVIPAROUS QUADRUPEDS. 237

of the fourth family ; for which reafon we
think the method of M. Briilon is to be pre-
ferred. It muft be confeffed, however, that
this laft, in which the author has ufed all the
characters together, as he has done with re-
fpect to the quadrupeds, appears very com-
plicated at firft fight ; but when it is re-
duced into a table, as we have done, all its
divifions may be readily diftinguifhed ; and
any bird may be eafily known by attending
to the characters according to their arrange-
ment. See table the third at the end of
this volume.

CHAP. IV.

Concerning Oviparous Quadrupeds, and
< Serpents.

T INN^EUS claffed together, in his fyf-
■*-' tern, under the denomination of am-
phibia, the oviparous quadrupeds, ferpents,
and cartilaginous fifhes : but JVL Dauben-
ton obferves, that the word amphibious
cannot be applied to any peculiar ciafs of
animals ; becaufe, if the expreffion be ap-
plied to animals who live as long as they
pleafe either in the air or in the water, there
are none which poffefs that advantage ; and

if

238 OVIPAROUS QUADRUPEDS.

if it be applied to terreftrial animals, which
are able to remain a certain time in the wa-
ter, or to aquatic animals, which are capa-
ble of living a certain time in the air, all
animals would be amphibious. He there-
fore makes two orders of oviparous quadru-
peds and ferpents, and arranges the amphi-
bia nantes of Linnaeus among the fifties.

The oviparous quadrupeds form the fourth
order of animals in the divifion of M. Dau-
benton. Their organization is confiderably
perfect, fince like the quadrupeds, cetaceous
animals, and birds, which precede them,
they have a head, noftrils, and internal ears.
But they differ in the following characters :

1. They have but one ventricle m the heart.

2. Their blood is almoft cold. 3. They
infpire and expire the air at long inter-
vals. 4. They are oviparous, and confe-
quently without breads ; this laft character
is common to them with the. four orders of
animals which follow them. Laftly, the
exiflence of four feet without hair, is pecu-
liar to this order.

M. Daubenton remarks, that the feveral
genera of this order of animals differ too
much from each other, to admit of any ge-
neral defcription applicable to the whole.
He therefore applies the general characters
in the hiftory of each genus ; as for example,
at the words tortoife, lizard, toad, frog,
&c. in the fecond volume of the Natural

Hiftory

SERPENTS. 239

Hiftory of Animals, which compotes part
of the Encyclopedic Methodique.

As the methodical difpofition, and the cha-
racters of the orders of oviparous quadru-
peds, as laid down by this celebrated natu-
ralift, are the moft accurate and complete of
any which have yet come under my obfer-
vation, I have united all the divifions of M.
Daubenton from the claffes to the fpecies ;
becaufe thefe laft are no more than a hundred
in number. See the fourth table.

Serpents form the fifth order of animals
in the divifion of M. Daubenton. The
fcales with which they are covered, and the
abfence of feet and fins characterize them very
well. They have a head, noftrils, internal
ears, a lingle ventricle in the heart, the
blood almoft cold, their refpiration is made
at long intervals, and they lay eggs like the
oviparous quadrupeds. Serpents have nei-
ther neck nor moulders, and the fcales which
cover them are of three kinds. They are
either rhomboidal, and cover each other in
the manner of tiles, which Linnaeus calls
fquammae ; or they are of a long fquare form,
touching without covering each other; Lin-
naeus calls thefe fcuta : they are only obferv^
able on ferpents j when they are very lmall
and of the fame form they are called fcut-
tella ; or laftly, they confift of rings encirc-
ling the bodies of ferpents, as is feen in the
amphyfbena.

, Serpents,

24° SERPENTS.

Serpents, though without feet, fometimes
move with confiderable fwiftnefs, by leaning
firft on their anterior part, railing up the
middle, and bringing forward the pofterior
part of their body j by which means they raife
themfelves on their tail, and fpring to fome
diftance, in order to feize their prey. They
caft their fkin once or twice in the year.

Some ferpents are venomous ; out of
131 fpecies noted by Linnseus, 23 are dan-
gerous, according to that naturalift. All
thefe animals, whofe bite is venomous, have
on each fide of the upper jaw, a tooth much
larger than the others, together with a refer-
voir filled with a peculiar liquor, which
paffes into the wound through a perforation
in the tooth.

It is eftablifhed, by the moft authentic
teftimony, that fome ferpents are of a pro-
digious fize. Mr. Adamfon, from very exacT:
data, fixes the magnitude of the largeft fer-
pents at 40 or 50 feet in length, and a foot,
or a foot and a half in thicknefs. M. Lau-
renti has paid greater attention than any
other naturalift to the claffification of fer-
pents. He diftributes them into feventeen
genera ; but the difficulty of obferving the
diftin&ive characters, has prevented M. Dau-
benton from adopting his method; this laft
naturalift has therefore followed Linnaeus in
the fifth table. I have inferted the divifions
and characters of ferpents from the genera to

127

FISHES. 241

127 fpecies, noted by M. Daubenton. Sec
table the fifth.

CHAP. V.

Of Fifhes.
Ichthyology.

FISHES are animals very different from
the foregoing : their interior organs are
of a peculiar ftrudture, as we fliall obferve
in our abridgment of phyfiology. They are
diftinguifhed from other animals by their
having no feet, but fins, by which they
move in the water, and by their refpiring
water inftead of air. It is much more diffi-
cult to make obfervations on fifhes than on
other animals, and for that reafon their na-
tural hiftory is in a much lefs advanced ftate.

In order to underftand the methodical di-
vifion which we propofe after Artedi, Lin-
naeus, and Gouan, it will be necefTary to
take a curfory view of the anatomy of their
external parts. The bodies of fifties may be
divided into three parts ; namely, the head,
the trunk, and the fins.

The head of thefe animals is differently
formed. It is either flattened horizontally,
or laterally, or elfe round; naked, or co-

Vol. IV. Q_ vered

242 FISHES.

vered with fcales ; fmooth, or covered with
afperites, tubercules, & c. Their mouths are
obferved to have lips either of fie 111 or of
bone, with appendages, or foft and very
moveable barbulaa ; the teeth fixed either
to the jaws, the palate, the tongue, or the
throat ; the eyes two in number, motionlefs,
and without eyelids ; the perforations of the
noftrils double on each fide the opening of
the gills or branchiae -, the opercula, or round
triangular or fquare bones defigned to clofe
the aperture of the branchiae ; the branchial
membrane placed beneath the opercula, fuf-
tained by feveral bones in the form of an
arch, whole number varies from two to ten.
This membrane is folded up beneath the
opercula, and muft be well examined with
refpect to its ftructure and varieties, becauie
the characters of the genera are moil com-
monly taken from the number or form of
its radii.

The trunk is of various forms as well as
the head j it is either round, globular, long,
fiat, or angular. The obferver mull take
notice of the lateral line, which feems to
divide each fide of the body into two parts ;
the thorax placed beneath the gills at the
commencement of the trunk, and contain-
ing the heart and the branchiae ; the belly,
whole ribs form the principal fupports of
the fins continued from the head to the
tail, and which contains the ftomach, the

inteftines,

FISHES, 243

inteftines, the liver, the air bladder, the
parts of generation ; the opening of the anus,
which is common to the inteftines, the
bladder, and the generative parts ; laftly,
the tail, which terminates the trunk, and
is of various forms and magnitudes.

The fins, pinnce natatorice, are formed of
membranes fupported on fmall radii, fome
of which are hard, bony, and: terminate in
a fharp point, which characterizes the fifties
called acanthopterygiani, fo denominated by
Artedi ; others are flexible, foft, obtufe,
and as it were cartilaginous, which charac-
terizes the fifhes called malacopterygianu
Five forts of fins are diftinguifhed with re-
flect to their fituation ; the dorfal, the pec-
toral, the abdominal, together with thofe of
the anus, and of the tail.

The dorfal fin is impair j it maintains the
fifh in equilibrium, and varies in fituation,
number, figure, proportion, &c.

The pectoral fins are fituated at the aper-
ture of the gills ; they are two in number,
and perform the office of arms, and fometimes
of wings. They differ as to the place of
their infertion, extent, figure, &c.

The abdominal fins are of the greateft
importance to be known, becaufe their fitua-
tion has been affumed by the celebrated Lin-
naeus, as a diftinctive character in the clafiifica-
tion of fifhes. Thefefins are placed at the infe-
rior part of the body, under the belly, before
Q^2 the

244 FISHES.

the anus, always lower and nearer to each
other than the perioral fins. They are fome-
times wanting; and as Linnasus has com-
pared them to feet, he calls thofe fifhes
which are without them apodes ; but they
exift in the greateft number of fifhes. Their
infertion varies ; when they are placed for-
ward or beneath the aperture of the gills,
and the pedtoral fins, they are called jugu-
lar ; and the fame name is likewife applied
to the fifhes in which it occupies this place.
If they be attached to the thorax behind
the opening of the gills, they are then called
thoracic ; and the fifhes which poflefs this
ftrudture are diftinguifhed by the fame name
in the method of Linnaeus. Laftly, when
they are placed beneath the belly, nearer the
anus than the pedtoral fins, they are denoted
by the name of abdominal, which term is
likewife applied to the fifhes diftinguifhed by
this ftrudture.

The fin of the anus is impair. It occu-
pies either wholly, or in part, the region
fituated between the anus and the tail ; it
differs in form, extent, and number, though
it has not been obferved double, excepting
in the gold fifh of China.

The tail fin is placed vertically at the
extremity of the body, and terminates the
tail. It is the rudder of the fifh, or inftru-
ment by the various motions of which it
changes its direction at pleafure. It like-
wife

FISHES. 245

wife exhibits many varieties in its form,
adherence, connection, extent, &c.

After theie details refpecting the external
anatomy of fifties, we (hall proceed to men-
tion the methodical divifions of naturalifts.
Before the time of Artedi, no naturalift had
attempted to arrange fifties in a methodical
manner; though feveral methods were be-
fore ufed for the clarification of other ani-
mals. This philofopher propofed a fyftem
of Ichthyology, founded on the nature of the
bones of the fins, whether hard or foft,
pointed or obtufe, and on the form of the
gills. He afterwards attempted to multi-
ply the divifions by attending to the other
parts ; but a premature death terminated his
labours. Linnaeus attempted to eftablifh an
Ichthyologic method, from the various fitu-
ations of the belly fins ; and Mr. Gouan, a
celebrated profefibr at Montpelier, has very
fkilfully combined the two fyftems of Ar-
tedi and Linnasus. This naturalift firft di-
vides fifties into fuch as have their gills com-
plete ; that is to fay, confiding of an aper-
ture and a complete branchial membrane,
and thofe which have their gills imperfect ;
that is to fay, wanting either the opercula,
or the branchial membrane, or both. The
firft are afterwards diftinguifhed from each
other by the form of their fins. Thefe parts
are in fact compofed either of hard and ftiarp
bones, or foft, and as it were cartilaginous
0^3 radii,

246 INSECTS.

radii. Thefe differences constitute three claf-
fes of fifties, namely, 1. The acanthoptery-
giani. 2. The malacopterygiani. 3. The
branchioftegi. In each of thefe claffes of
fifhes, the belly fins are either wanting, or
placed at the neck, thorax, or belly. Mr.
Gouan has divided each clafs into four or-
ders ; that is to fay, apodes, jugular, tho-
racic, and abdominal.

The diftinttive characters of the genera,
which immediately follow thefe divifions,
are founded on the form of the head, of the
mouth, of the branchial membrane, and
more particularly on the number of radii
which fupport this membrane. See Table VI.

CHAP. VI.

Concerning Infects.

Entomology.

TNSECTS are animals which are known
■*■ by the form of their body, which is di-
vided as it were into rings, and by two
moveable horns which they have on their
head, and are diftinguifhed by the name
of antennae. Infects compofe one of the
moft numerous claffes of animals, doubt-
lefs, on account of their minutenefs ; for

it

INSECTS. 247

it has been obferved, the fmaller thefe
creatures are, the more numerous is their
production. The hiftory of thefe animals
is highly agreeable and amufing, and per-
haps not the lead in point of utility ; fince
difcoveries refpefting their properties may
pro^ exceeding ufeful in the arts, and in
medicine.

The claries of infefts exhibit refemblances
with almolt every other animal, with re-
fpeft to their manners, form, habitations,
&c. Some walk like quadrupeds ; others
fly like birds ; others again fwim, and live
in the water like fi flies ; and laftly, there are
others which leap, or crawl along, like certain
reptiles. This analogy may even be carried
much farther, by a full examination of the
ftrufture of their extremities, their mouth,
their internal organs, &c.

In lefts externally confidered, are com-
pofed of three parts ; namely, the head, the
thorax, and the abdomen.

The head differs in its form, fize, and pofi-
tion. It is fometimes very large, and fome-
times very fmall,% with refpeft to the bulk
of the infeft. It is either round, fquare,
or long; fmooth, rough, tuberculated, or-
tufted with hair. We may obferve the an-
tennae placed near the eyes, confifling. of
different articulated and moveable pieces,
refembling a thread terminated either by
Q^4 a point

24^ INSECTS.

a point or a knob. The form of thcfe
organs muft be carefully diftinguifhed,
becaufe this character is almoft always ufed
to diftinguifh the genera. 2. The eyes -y
which are of two forts, either in facets, or
refembling net-work, fmooth and fmall.
Thefe organs are very large in fomc infers,
and in others very fmall. Their number
is various ; there are infedls which have
only one eye, as the monoculus ; others
have two, five, or even eight, as for exam-
ple the fpider, &c 3. The mouth; which
is formed either of ftrong and corneous jaws,
moveable laterally, or confifts of a trunk of
various lengths dilated, fpiral, &c. ; or a Am-
ple, cleft, &c. This part is frequently or-
namented with fmall moveable appendices,
called antennulae, to the number of two or
four.

The thorax is the ftomach of infedls. It
is placed between the head and the belly,
and is either round, triangular, cylindric,
thick, flender, &c. It may be confidered
as compofed of fix faces, like a cube, which
form it fometimes has. The face, or ante-
rior extremity, is hollowed to receive the
head. This articulation is fometimes made
only by a part as fmall as a thread, as in flies.
The pofterior extremity is ufually rounded
and articulated with the firft ring of the abdo-
men, and is fometimes joined with this part
only by a thread. The fuperior furface is ei-
ther

INSECTS. 249

ther flat and fmooth, rounded, prominent,
with appendices, or tubercles, or terminated
by a kind of border, turned up, which confti-
tutes the thorax marginatus. The wings arc
attached at the pofterior part of this furface.
Moil infects are provided with thefe organs ;
but as they differ Angularly from each other,
and the principal diviiions of claffes adopted
by methodical writers are founded on thefe
differences, it will be neceffary to attend
more particularly to them.

The wings are either two or four in num-
ber ; among thofe which have two tranfpa-
rent wings, as the fly, the gnat, &c. thefe
wings always have beneath the place of their
infertion a flender thread terminated by a
round button, called balancers, haheres,
which is covered by a concave membra-
nous fubftance. In a great number of in-
fects thefe two wings are very ftrong, and
folded up under hard, horny, moveable co-
verings, called fheaths, or elytra. Thefe
differ in form ; fome cover the whole ab-
domen j others are, as it were, cut tranf-
verfely, and cover only a part ; fome are
hard, and others foft, and moft of them
towards the top of the future, or line, at
which they are applied to each other, have
a fmall triangular piece affixed to the tho-
rax, which is called fcutellum ; but this
piece is wanting in fome. Laftly, in many
infects the elytra are fattened together, and

are

2$0 INSECTS.

are formed of one motionlefs piece. The
wings are often four in number, and are thin
membranes, and tranfparent, as in the li-
bella, the wafp, &c. or they are covered on
each furface with a coloured powder, which,
under the microfcope, appears to confift of
fcales, placed over each other like tiles, im-
bricatim. .

The inferior part of the thorax is irre-
gular, confifting of feveral pieces fattened to
each other ; and fome of the legs are fixed to it.
The number of legs varies in infects ; fome
have fi#, and others eight, like fpiders :
others have ten, as the hornet. Laftly,
there are infects which have a much larger
number; the wood-lice have fixteen ; and
fome of fcolopendra, and centipedes, have as
many as feventy, and one hundred and twen-
ty, on each fide. Among thofe which have
no more than fix, eight, or ten, they are all
attached to the thorax, according to Geof-
froy -, among thofe which have a larger num-
ber, fome are inferted in the rings of the
belly.

The leg of an infect is always compofed
of three parts ; the thigh, which joins to
the body, the leg, and the tarfus. There
is often an intermediate piece between the
body and the thigh. The tarfus is formed
of many pieces, or rings, articulated toge-
ther, whofe number varies from two to five.
In fome infects, the tarfus is more confider-

able

INSECTS. 25I

able in the fore than in the hind feet; a
circumftance which eftablifhed an analogy
between thefe creatures and many quadru^
peds, whofe fore-feet have a greater number
of digits than the hinder. M. Geoffroy has
availed himfelf of this character, in his di-
viiion, as we mall hereafter fee. The tarfus
is terminated by two, four, or fix, fmall '
claws, or hooks, and is often furnimed with
brufhes, or fpungy balls, on its lower part,
by means of which the infect is capable of
walking on the moft polifhed fubftances,
fuch as glafs, &c. in any pofition.

On each fide of the thorax, one or two
oblong, oval apertures are obferved, which
are called ftigmata, through which the in-
feci: refpires.

The third part of infects is the abdomen.
It is moft commonly compofed of corneous
rings, or half rings, which flip over one an-
other; in fome the rings are not obferved, and
the abdomen appears to be formed of a fingle
piece : it is ufually larger in males than fe-
males. The parts of generation are placed
at its extremity ; a ftigma is obfervable on
the fide of each ring, except the two lafh
Many infects have flings at the pofterior part
of their abdomen, fome of which are fharp and
piercing, others in the form of a fiw, and
fome of that of a gimblet. They ferve ei-
ther as inftruments of defence, or to pene-
trate

252 INSECTS.

trate fubftances in which the infetts depofit
their eggs.

The moft Angular phenomenon, in which
infects differ intirely from moft other ani-
mals, confifts in the changes of ftate through
which they pafs, or the metamorphofes they
are fubjedted to, before they become per-
fect infects. There are fome infects, and
almoft all the clafs of aptera, wfych do
not undergo thefe changes, but the great-
er number are fubject to them ; the in-
fect does not come out of the egg with
the form of the mother, but in that of a
worm, with or without feet, the ftrudturc
of its head and the rings being exceedingly
various. This firft ftate is the caterpillar ;
under this kind of mafk, the infect eats,
grows, moves, and changes its fkin feveral
times. When it has grown to its full fize,
it changes its fkin for the laft time, and no
longer appears under the form of a worm,
but under a different form, called nympha
chryfaltSj aurelia.

M. Geoffroy diftinguifhes four kinds of
nymphae : the firft is that which does not
refemble an animal; a few rings only are
obferved at the lower part, and the upper
part exhibits indiftindt impreffions of an-
tennas, legs and wings. The fkin of this
kind is hard, cartilaginous, and it has only
a flight motion in its rings. The butterfly,
phalaena, &c. are of this kind.

The

INSECTS. 253

The fecond kind of chryfalis admits of
the parts of the perfedt animal being dif-
tinguifhed beneath a thin and very foft
fkin. It is motionlefs, like the forego-
ing. Infedts with hard coverings to their
wings, thofe with four naked wings, and
thofe with two wings, afford examples of
this kind.

The third fpecies, is that whofe parts are
perfectly developed, and which move ; fuch
are thofe of the gnats and infedts which pafs
the two firft ftages of their life in the water.

Laftly, the fourth fpecies comprehends
thofe which refemble the perfedt infedts in
the form of their body, their antennae, and
paws : thefe nymphae move, and eat ; they
differ from perfedt infedts only in the
want of wings, and in their being incapable
of procreating. The nymphs of the libella,
of the bug, of grafshoppers, and of crickets,
&c. are of this kind.

Infedts, like other animals, were only dif-
tinguifhed by the ancient naturalifts from
the places of their habitation. No one be-
fore the time of Linnaeus attempted to dif-
pofe them methodically, according to diftin-
guifhing charadters. After Linnaeus, to whom
we are indebted for the firft fyftematic divi-
fion of thefe animals, M. GeofFroy attempt-
ed to clafs them in a more accurate manner;
his divifion of fedtions in genera is a mafter-
piece of the kind, for precifion, accuracy,

and

254 INSECTS.

and perfpicuity : we fhall therefore follow
his fyftem. M. Fabricius has fince availed
himfelf of the form of the jaws to divide
infers.

M. Geoffroy divides infects into fix fec-
tions, according to the abfence, the number,
and the ftru&ure of the wings : the firft
fection includes the coleoptera, or infects
whofe wings are covered with cafes. Their
mouth, which is armed with two lateral
and corneous mandibles, forms likewife a
general character of this fection. The May-
bug exhibits both thefe characters.

The fecond fection comprehends the he~
tniptera, whofe fnperior wings are either
in a fmall degree thick and coloured, or
rather hard and opake ; but as the character
of the wings is i.ot flrongly marked in this
fection, it is replaced by that of the mouth,
which is conftant. This mouth is a long
and flender trunk, turned inwards between
the feet : the wood-bug and the cicada are
of this fection.

The third fedtion is compofed of tetrap-
tera, with farinaceous wings, the four wings
being coloured by a fcaly powder. Thefe
have a trunk more or lefs long, and often
of a fpiral form, as in the butterfly : Lin-
naeus calls thefe lepidoptera.

In the fourth fection are placed the te-
trapteray with bare wings. Their four
wings are membranous, and their mandibles

are

INSECTS. 255

are hard : the wafp is of this kind. Linnaeus
has made two orders of thefe infe&s ; name-
ly, the neuroptera, whofe anus has no
fling, and whofe wings have nervous
marks ; and the hymenoptera, which have
the anus armed with a fting, and the wings
membranous, without any very apparent
nerves.

The fifth fe&ion contains the diptera,
or infedts with two wings ; their mouth is
moft commonly in the form of a trunk, and
they have ballancers under the infertion of
their wings.

Laftly, in the fixth and laft fe&ion are
clafTed, the aptera, or infefts without wings,
fuch as the fpider, the loufe, &c.

Befides thefe primary divifions, M. Geof-
froy has eftablifhed others, to facilitate the
diftindion of infefts. See Table VII.

CHAP.

256 WORMS.

CHAP. VII.

Of Worms.

TyORMS are foft animals, of a very
*^ different form from infe&s, with
which they have been confounded by feve-
ral naturalifts, their organization being lefs
perfedt than that of thofe animals. They
have no bones, properly fpeaking ; and their
members are not conftrudted like thofe of
infefts, neither are they, like them, fubject
to pais through different ftates. Their or-
gans, deftined for the purpofe of generation,
are not known ; many worms have no head
perfectly formed ; and laftly, the abfence of
feet and fcales diftinguifh them from all
other creatures. The clafs of worms is the
mod numerous, and the lead known, of all
animals. There are few organic fubftances,
either living or dead, in which certain worms
are not found, that fubfift and are nourifhed
within them. Moft naturalifts have placed
worms and polypi in the fame clafs ; but it
would perhaps be better to feparate them,
fince their internal ftru&ure and fun&ions
perfectly diftinguifh them from each other.
We know that moft worms contain a heart,

and

WORMS. 257

and veflels, but nothing fimilar has been dif-
covered in polypi. The worms we now fpeak
of mi] ft not be confounded with the larvcz
of infecfts or caterpillars, which have likewife
been called worms, merely on account of their
form. Their head, furnifhed with mandi-
bles, and their legs, which are more or lefs
numerous, confifting commonly of fix, af-
ford characters by which they may be eafily
diftinguifhed.

Worms have a considerable degree of ac-
tivity, and in general love moifture. Some
have not a head which can be eafily diftin-
guifhed •, moft of them are hermaphrodites.
Such as have a head, have two moveable
horns, which they can retraft, and are called
tentacula. All the worms, of which we are
now giving an abridged account, have the
property of being re-produced, when cut
through ; a circumftance which {hews, that
their organization is fimple, and refembles
that of polypi.

This clafs of animals may be divided into
four feftions : the firft contains the naked,
or bare worms, whofe organization is belt
known, and which in their leading character
refemble other animals ; in the fecond, we
lhall place worms which have a teftaceous
covering, or fhell-worms ; their organs are
lefs known than thofe of the former fe<ftion ;
the valuable refearches of Mr. Adanfon

Vol. IV. R , prove,

258 ANIMAL FUNCTPONS.

prove, however, that their ftructure refem-
bles that of naked worms. The third fection
will contain worms with a cruftaceous co-
vering ; their organization is not fo well
known as that of the foregoing, their ex-
ternal form and the ftructure of their mouth
only having been examined. And laftly,
the fourth fection will include the polypi.
The methodical divifions of thefe different
fections have already afforded employment to
many naturalifts ; Lifter, Linnasus, Klein,
Ellis, Pallas, D'Argenville, are thofe of
whofe affiftance we have availed ourfeives, in
the imperfect divifion exhibited in our eighth
table. See Table VIII.

CHAP. VIII.

The Functions of Animals confidered, from
Man to the Polypus.

'THE characters peculiar to living and
-^ organized bodies, confift, as we have
already obferved, in the different functions
executed by means of their organs. We
have confidered thofe of vegetables ; the or-
der we have adopted now leads us to the
functions of animals.

That part of the art of medicine, in which

the

Animal functions. 259

the functions of animals are examined, is
called phyfiology. This ufeful and valuable
fcience ought not to be confined to the fingle
confiderationof the human fpecies, but mould
be extended to all animals : in this point of
view, we fhall curforily pals over the animal
kingdom.

The' functions of animals are reducible td
the following :

I. Circulation.

II. Secretion.

III. Refpiratiofl.

IV. Digeftion.

V. Nutrition.

VI. Generation.

VII. Irritability.

VIII. Senfation.

Thefe different functions are obferved iri
man, quadrupeds, cetaceous animals, birds,
fifhes, oviparous quadrupeds, ferpents, and
infe&s. Worms and polypi do not poffefs
them all, neither do ferpents nor infedts
poffefs them in the fime degree.

I. The circulation is one of the moil im-
portant functions. It is indifpenfably ne-
ceffary to maintain life. The organs by
which it is performed, are the heart, the ar-
teries, and the veins.

The heart is a conical mufcle, towards

the apex of which are two cavities, called

ventricles ; and at its bafe, two other veffels,

called auricles. A large artery, named the

R 2 aorta,

260 ANIMAL FUNCTIONS.

aorta, ilTues from the left ventricle, and
distributes the blood to the various parts of
the body ; another artery, of equal magni-
tude, iffues from the right ventricle, which
is called the pulmonary artery, becaufe it is
fpread into ramifications in the lungs. The
right auricle receives the blood which re-
turns from every part of the body, by the
two venae-cavae $ whence the fluid pafles into
the right ventricle : from this laft it is trans-
mitted to the lungs, by the pulmonary arte-
ry, and is returned, by the pulmonary veins,
into the left auricle, and thence to the left
ventricle, from which it is propelled to all
the parts of the body through the aorta. This
motion, as it takes place in man, conftitutes
two kinds of circulation ; that of the whole
body, and the pulmonary circulation. The
latter was known before the former. Har-
vey, an Englifli phyfician, difcovered the
general circulation.

This fun&ion is performed in quadrupeds,
cetaceous animals, and birds, abfolutely in the
fame manner as in the human fpecies. In
fifties, the heart has but one ventricle, and the
lungs, or gills, do not receive blood, by
means of a peculiar cavity of the heart. Rep-
tiles refemble fifties in this refpedt. The heart
of infedts and worms confifts of a feries of
nodules, which contract one after the other ;
their veflels are very fmall, and their blood
cold and colourlefs. Polypi have neither

heart

ANIMAL FUNCTIONS. 26l

heart nor veflels ; and are inferior to vege-
tables, with refpedt to this fun&ion.

II. Secretion is a fun&ion, by which dif-
ferent organs feparate, from the blood, juices
deftined to particular ufes, as the bile in the
liver, &c. This function is one of the moil
general in animals, and is found in all the
clafles y but it is not poflible to attend to it in
each, without entering into too long a detail.
It will therefore be fufficient to obferve, that
in all animals, which have a true circulation,
the fecretions follow the fame laws as in man;
and that it even appears to take place in moft
animals which have not a heart. Befides the
analogy that neceflarily fubfifts between man
and animals which have the fame organs, with
refpedt to the fundions we are treating of,
certain clafles of animals exhibit peculiar fe-
cretions, which are not performed in the hu-
man fpecies ; fuch are the mufk and civet in
quadrupeds, fpermaceti among cetaceous ani-
mals, the oily fluid, with which birds fmear
their wings, the virulent fluid of the viper,
the adhefive fluid of the fcales of fifhes, the
acrid and acid juices of the bupreftis, ftaphy-
lini, ants, and wafps, among infe&s ; the vif-
cous mucilage of fnails, the colouring juices
of the purple fifh or murex, and a great many
others, which the natural hiftory of each ani-
mal difplays.

III. Refpiration, confidered in all animals,
is a function intended to bring the blood into
contad; with the fluid they inhabit : men and

R 3 quadru-

262 ANIMAL FUNCTIONS.

quadrupeds, for this purpofe, have an orgai^
called the lungs. This vifcus confifts of a
collection of hollow veficles, which are form-
ed by the expanfion of a membranous and
cartilaginous tube, called the arteria trachea,
and of blood-veffels, which form a great
number of areola? at the furface of the bron-
chial veffels : thefe veficles and veffels are
fuftained by a cellular, loofe, and fpungy fub-
flance, which forms the parenchyma of the
lungs. The air diftends the veffels by infpi-
ration ; the bafe of the vital air of the atmo-
fphere appears to combine with a principle
difengaged from the blood, and forms the
cretaceous acid, which is expired, together
with the mephitis. The matter of heat, fe-
parated from the vital air, unites with the
blood, and reftores thofe properties which it
had loft in paffing through the body.

This function is performed in the fame
manner in cetaceous animals ; excepting,
however, that as there is an immediate com-
munication between the auricles, thefe ani-
mals are capable of remaining a confiderable
time without refpiring.

Though the refpiration in birds be ana-
lagous to that of the animals laft treated of,
yet it appears to be much more extenfive.
Anatomifts have difcovered, in the abdomen
of birds, fpungy veficular organs, which
communicate with their lungs ; and thefe laft
extend even into the bones of the wings,

which

ANIMAL FUNCTIONS. 263

which are hollow, and without marrow, by
a channel placed at the upper parts of the
breafts, and which opens in the fuperior
part of the os humeri. This happy dif-
covery of Mr. Camper teaches us, that the
air paffes from the lungs of birds into the
bones of their wings -, and that this fluid,
rarefied by the heat of their bodies, renders
them very light, and Angularly affifts their
flight.*

Fifhes have gills, or branchiae, inftead of
lungs ; thefe organs are formed of membra-
nous fringes, difpofed on a bony arch, and
charged with a very great quantity of blood-
veflels. The water enters by the opening
of the mouth of fillies ; paffes through the
fringes, which are by that means feparated
from each other ; preffes and agitates the
blood, and paffes out through apertures fi-
tuated at the two lateral and pofterior parts
of the head, on which two moveable bony
valves, called opercula, are placed, and fuf-
tained by the branchial membrane. Du-
verney fuppofed that the brachiae feparate the
air contained in water. M. Vicq d'Azir,
who has paid great attention to the anatomy
of fimes, thinks that the water performs
the office of air in the branchiae of thefe ani-

* This is doubtful. See Mr. John Hunter's account
of certain receptacles of air in birds, which communicate
with the lungs. Philof. Tranfa&ions, vol. 74, for the
year 1774. T.

R 4 mals,

264 ANIMAL FUNCTIONS.

mals. It is certain, that as fifhes do not
refpire air, and convert it into cretaceous
acid, their blood does not poifefs the degree
of heat, which the air gives to iuch animals
as refpire it.

Infedls have no lungs ; they have two
tubes, or tracheae, placed along the back,
from which, on each fide, other fmaller
tubes iffue forth, and terminate at the lateral
part of each wing, by a fmall cleft, called
ftigma-: Thefe ftigmata appear rather to be
defigned to emit fome elaftic fluid, fince in-
fefts do not quickly die in a vacuum; though
they have convullions, and expire in a few
inftants, if the ftigmata be covered with oil
or varnifh. Worms have an organization,
flill lefs perfect. No kind of refpiration has
been obferved in polypi, which, with refpedt
to this function, are lefs perfect than vege-
tables, in which we have obferved the tra-
cheae.

IV. Digeftion confifts in the feparation of
the nutritive matter contained in food, and
its abforption, by peculiar veffels, called
chyliferous. It is performed in a channel,
which is continued from the mouth to the
anus, and which, in man, in enlarged to-
wards the upper part of the abdomen.
This enlargement is called the ftomach.
The alimentary canal afterwards becomes
narrower, is turned in different direc-
tions, and is diftinguifhed by the name

of

ANIMAL FUNCTIONS. 265

pf the inteftines. This#long tube, which is
formed of mufcles and membranes, retains
the aliments, fo as to extract all the nutri-
tive matter they contain. There are like-
wife other glandulous organs, near the fto-
mach, whofe office is to prepare the fluids
requifite to ftimulate the ftomach and intef-
tines, and to extract the nutritive part of
the food : thefe organs are the liver, the
fpleen, and the pancreas. The bile and
pancreatic juice flow into the firft infeftine,
called the duodenum, and mix with the
food. Before this mixture is performed, the
aliments are diifolved in the ftomach, by the
gaftric juice.

The whole courfe of the inteftines is co-
vered with vafcular apertures, deftined to ex-
tract the chyle. Thefe veflels convey it into
the receptaculum lumbare, in the thoracic
duct, and the chyle is poured into the left
fubclavial vein, in which it mixes with the
blood. Such, in a few words, are the me-
chanifm and phenomena of digeftion in man.

Quadrupeds differ greatly in the form of
their teeth, ftomach, and inteftines : fome of
thefe animals, as the ant-eater, and the fcaly
lizard, which live on foft food, have no teeth;
others, fuch as the floth and the armadillo,
have only grinders ; others, as the elephant, and
fea-cow, have molar and canine teeth ; laftly,
the greater number have the three kinds of
teeth, mojar, canine, and incifivej but their

number,

266 ANIMAL FUNCTIONS.

number, pofition, and ftrength, are fubjecfl to
great variations. The moil finking circum-
fiance in this various ftru&ure of the teeth,
is, that, according to the remark made by
Ariflotle, Galen, &c. there is a conftant re-
lation between the number and pofition of
thefe bones, and the form of the flomach.
In fa6t, all quadrupeds, which have incifive
teeth in both jaws, as the horfe, the ape,
the fquirrel, the dog, the cat, have no more
than one membranous ventricle, as in man;
the anatomifts call thefe animals monogaf-
trica: and in thefe the digeflion is perform-
ed ahfolutely in the fame manner as in the
human fpecies. Quadrupeds, which have
incifive teeth only in the inferior jaw, zvzpoly-
gajirica, and ruminating j fuch are the camel,
the goat, the ram, the ox, the flag, &c. Thefe
quadrupeds, which are ufually bifulc, and
armed with horns, have four flomachs ; the
fir ft, called in oxen the paunch, is the largeft,
and is divided into four other cavities ; it
receives the aliments at the fame time with
the fecond, which opens into the paunch by
a large orifice. The herbaceous aliments,
contained in thefe organs, dilate, and the air
becomes rarefied ; the nerves of thefe vifcera
are flimulated, and an anti-periftaltic motion
is excited, which returns them, through the
oefophagus, into the mouth; where they are
again mafticated by the molar teeth, and re-
duced

ANIMAL FUNCTIONS. 267

Juced into a kind of foft pafte. In this ftate,
together with the drink, they are conducted,
by a new deglutition, into the third fto-
mach, called the omafus, by means of a
dud paffing from the oefophagus to this laft
ventricle. Laftly, they pais from the omafus
into the fourth ftomach, where they are truly
digefted. The intefrines of ruminating ani-
mals, are likewife much more extended than
thofe of monogaftric quadrupeds. Cetaceous
animals perfectly refemble thefe laft, in the
mechanifm of the now treated of function.
Birds differ from each other in the ftructure
of their ftomach -y in fome it is membranous,
and in others flefhy, or mufcular. The firft
fort, which may be called hymenogajlrica,
are carnivorous -, all birds of prey are of this
fpecies. Their ftomach contains a very ac-
tive juice, capable of foftening bones, ac-
cording to the experiments of Reaumur :
their bile is likewife very acrid. The fe-
cond, which may be called miogajirzca, fub-
fift only on grain ; their ftomach is formed
of a quadrigaftric mufcle, armed with a hard
and thick membrane, proper for trituration :
thefe birds have likewife a double ccecum.

Fifhes have a membranous long ftomach,
with many appendices ; their inteftines are
in general fhort. Reptiles exhibit the fame
ftrudture ; their ftomachs are capable of an
aftonifhing degree of diftenlion. Serpents
are often feen to fwallow intire animals,
much larger than themfelves.

Infects

268 ANIMAL FUNCTIONS,

Infers have a ftomach, and inteftines,
which are well organized. Swammerdam
and Perrault affirm, that the mole cricket has
four ftomachs. Their ftomachs are divided
into four cavities, as may be eafily {ecn by
differing this infect, which is very common,
and much feared by gardeners. Worms have
a very irregular ftomach, and likewife fmall
inteftines. The polypus feems to be merely
a ftomach, for it digefts very quickly : the
fame aperture ferves this creature both as
mouth and anus.

V. Nutrition is a confequence of digeftion
and circulation. As the folids always lofe,
or become diminifhed, by the motions they
perform, and require to be repaired, this is
performed by nutrition. In the early part
of life, they increafe in bulk, and the ani-
mal grows. The cellular membrane is ufu-
ally confidered as the organ of this function,
and the lymph as the fluid proper to reftore
the folids. It appears, neverthelefs, that
each organ is nourifhed by a peculiar and
proper matter, which it feparates, either
from the blood, the lymph, or fome other
fluid which paifes through it. For example $
the mufcles are maintained by the fibrous
matter, which they feparate from the blood;
the bones extract calcareous phofphoric fait,
and lymphatic matter •> the pure lymph dries
in laminae on the cellular texture; the con-

creflible

ANIMAL FUNCTIONS, 269

creffible oil being at th6 fame time depofited.
Each organ, therefore, is nourimed in a
peculiar manner, and in each, nutrition is a
true fecretion. Quadrupeds and cetaceous
animals perfectly refemble man, with regard
to this function. The fame remark applies
alfo to birds : but it is performed much lefs
quickly with fifties ; for which reafon thefe
animals live a very long time : the age of
fome of them is not known ; but in general,
the flower the nutrition and the growth, the
longer the life.

Infe&s exhibit nothing remarkable with
regard to this function. It mufl only be
obferved, that they grow only in the form
of larvae, and not in that of the chryfalis,
or of the perfed: infed:. Swammerdam
and Malpighi have proved, that the larva
contains a perfed infed:, ready formed be-
neath a number of fkins. The caterpillar
likewife contains the butterfly, whofe wings
and feet are doubled up.

In worms and polypi, nutrition is per-
formed in the cellular membrane, and is
likewife performed in vegetables, by means
of the reticular and veficular membranes,

VI. Generation, considered in all animals,
is performed in many different manners ;
moft of them have different (cxts, and re-
quire conjunction. Such are the human
fpecies, quadrupeds, and cetaceous animals.
The females of quadrupeds have a matrix,

feparated

2JO ANIMAL FUNCTIONS*

feparated into two cavities, uterus hicornis^
and a confidefable number of teats ; they
have not the menftrual flux; moft of them
bear feveral young at a time ; the time of their
geftation is fhorter ; feveral have a peculiar
membrane to receive the urine of the foetus;
this membrane is called allantoides.

The generation of birds is very different.
The males have a very ftrong and imperfo-
rated genital organ, which is often double.
The vulva, in females, is placed behind the
anus $ the ovaria have no matrices ; and
there is a duel, for the purpofe of convey-
ing the egg from the ovarium into the in-
terlines ; this paflage has been called oviduc-
tus. The egg of pullets has exhibited un-
expected facts to phyfiologifls, who have ex-
amined the phenomena of incubation. The
moft important difcoveries are thofe of Mal-
pighi and Haller. The latter found the
chicken, perfectly formed, in eggs which
were not fecundated.

There is no determinate conjunction among
fillies ; the female depofits its eggs on the
fand, over which the. male paries, and emits
its feminal fluid, doubtlefs for the purpofe
of fecundating them -, thefe eggs are hatch-
ed after a certain time.

The males of feveral oviparous quadru-
peds have a double, or forked organ. A-
mong ferpents, the viper is not viviparous.

Infedls alone, exhibit -all the varieties

which

ANIMAL FUNBTIONS. 27I

which are obferved in other animals. There
are fome, and indeed the greater number,
which have the fexes in two feparate in-
dividuals ; among others, the re-production
is made either with or without conjunction,
as in the vine-fretter, Puceron ; one of thefe
infects, confined alone beneath a glafs, pro-
duces a great number of others. Mr. Bon-
net has eftablifhed this fact, by experiments
very carefully repeated. The organ of the
male is inclofed in the abdomen, and may
be caufed to appear, by lightly preffing the
extremity of this part. It is ufually armed
with two hooks, to feize the female. The
place of thefe organs is greatly varied ; with
fome it is at the upper part of the belly,
near the breaft-plate, as in the female of the
dragon-fly; in others, it is at the extremity
of the antenna, as in the male fpider. In-
fects multiply prodigioufly, and are almoft
oviparous, except the wood-loufe.

Worms are hermaphrodites ; each indi-
vidual has two fexes, and the conjunction is
double, as is obferved in the earth-worm
and the fnail.

Mr. Adanfon adds, that bivalves, fhell
animals, or concha, have no organs of ge-
neration, and reproduce their young without
conjunction ; thefe worms are viviparous.
Univalves, or fnails, are oviparous ; the fmall
animals, whether they iffue from the belly

of

272 ANIMAL FUNCTIONS.

of the mother, or from eggs, have their
fhell ready formed.

Polypi are the fingular animals, with
refpeft to generation ; they are reproduced
by buds, or offsets : a bud is feparated from
each vigorous polypus, which is fixed to
fome neighbouring body, and grows : po-
lypi are likewife found on their furface, in
the fame manner as branches iffue from the
trunks of trees.

The mere phenomenaof generation compofe
the whole of our knowledge of the fubjedt;
and all the fyftems invented to explain this
myftery are attended with infurmountable
difficulties : they may be feen collected in
the Phyfiology of Haller, the Venus Phyfi-
que of Maupertuis, and the Natural Hiftory
of BufFon. Mr. Bonnet has treated largely
on this fubjedt, in his confiderations on or-
ganized bodies. M. De BufFon has given
an ingenious fyflem, which may be feen in
his work.

VI T. Irritability is the property which
certain organs, called mufcles, poffefs of con-
tracting or fhortening, by the aftion of any
ftimulus which touches them. Mr. Haller
has proved this valuable dodtrine inthemoft
perfpicuous manner. The mufcles of man,
of quadrupeds, of cetaceous animals, and of
birds, refemble each other ; they are all alike
red, compofed of fibres, united in bundles
of different forms, covered with iilver-^o-

luured

ANIMAL FUNCTIONS, 2J 3

loured membranes, called aponeurofes, and
terminated by flat, or round cords, named
tendons.

The mufcles of fimes are white, and much
more irritable than thofe which are red.
The irritability in oviparous quadrupeds and
ferpents is ftill ftronger, and lafts a long
time after the death of the animal. This ap-
pears to be a common property in all animals
whole blood is cold ; whereas, in animals
which have warm blood, it difappears in
proportion as that fluid cools.

Infedts have their mufcles placed within
their bones, which are hollow, and of the
nature of horn. This ftrudture may be well
obferved in the hollow thigh of the large
green grafshopper, and may likewife be eafi-
ly obferved in the lobfler.

The mufcles of worms are very pale, and
irritable ; they are likewife very ftrong in
covered worms, which have a heavy fhell
to carry.

Polypi are very irritable ; they contract
into a tingle point, and move their arms
with Angular agility -, yet their ftructure
does not appear to be mufcular.

It is from the property of irritability that
animals polfefs the power of tranfporting
themfelves from place to place, and of per-
forming a great number of motions, to re-
move noxious things, and to obtain thofe
which are ufeful. The hiftory of this func-

Vol. IV. S tion

274 ANIMAL FUNCTIONS.

tion ought, therefore, to include that of
animal motions. Standing, walking, leap-
ing, flying, creeping, or fwimming, are
combined adlions, or the refults of mufcular
contractions, in each clafs of animals. An
explanation of thefe, would require a de-
fcription of the extenfor mufcles of the
thigh of man, for ftanding ; that of the ex-
tremities of the figure of the body; the long
and acute face, and the thorax, laterally
comprefied, in quadrupeds, for leaping ; of
the ftrudture of the feathers, the fternum,
the pe&oral mufcles, the beak, the tail,
and the interior texture of the bones, of
birds, for flying. In this hiftory, likewife,
it would be neceffary to confider at large,
the mufcular annuli, the fcales, or the tuber-
cules, which anfwer the purpofe of feet in
reptiles; the form of the body, the ftrudure
of the fins, of the air-bladder, and its com-
munication with the ftomach, in fimes ; and
in infedis, the ftrufture, number, and pofi-
tion of the feet, the appendices of the tarfus,
the form, pofition, and nature of the wings,
the ballancers, Sec. But it is fufiicient, in
this place, to have mewn the importance of
thefe confiderations, and fuch as peculiarly
deferve the attention of the phyfiologift.

Laftly, there is another cenfideration,
which does not appear to have been fufli-
ciently attended to; namely, that a mufcle
may be regarded as a fecretory organ, appro-
priated

ANIMAL FUNCTIONS. 275

priated to the feparation of the fibrous and
irritable matter, of which we mall elfewhere
fpeak ; and that the imperfections of this
kind of fecretion ought to be very carefully
obferved by phyficians. We fhall refume this
fubject in our examination of the blood.

VIII. Senfibility is a function, by means of
which animals experience the fenfations of
pleafure and pain, according to the nature
of the bodies which are in contact with their
organs. The fenfes depend on the brain,
the medulla allongata, the fpinal marrow,
and the pairs of nerves, which ifTue in great
numbers from thefe three foci; without thefe
organs, feniibility could not exift. In order
to understand the mechanifm of this func-
tion more readily, we may divide into three
regions, thofe organs which are continued,
and feem to form but one, which phyfio-
logifts have called the fenfible man : thefe
three regions conhTt of the brain, the ce-
rebellum, and the medulla allongata; the
middle or part of communication confifts of
the nervous fibres, and the fenfitive expan-
fion, or dilated extremity, of the nerves. This
extremity exhibits various forms in different
organs ; in fome it is membranous and re-
ticular, as in the ftomach and inteftines; in
others, it is foft and pulpy, as at the bottom
of the eye, and in the labyrinth of the in-
ternal ear : in fome fituations, it has the form
of papillae, as beneath the fkin, on the
S 2 tongue,

2^6 ANIMAL FUNCTIONS.

tongue, and on the glands, &c. and in others
it is fpread into long, foft, and flat fibres,
as in the nafal membrane of Schneider.

The brain in man is larger and better or-
ganized than in other animals, and is the caufe
of his underflanding. In quadrupeds it is
much fmaller -, but on the other hand, their
nerves are more fenfible, and their fenfes more
acute, efpecially that of fmell, the organ of
which is much dilated, and as it were multi-
plied, by the number of ethmoidal lamina.
Their thick hairy fkin deprives them, in a
great meafure, of the fenfe of touch ; but their
tafte is very acute. The ear has the fame
apparatus, as in man.

Cetaceous fifh have fcarcely any brain, in
proportion to the mafs of their bodies ; this
organ is furrounded with an oily and thick
fluid; their fenfes are obtufe.

The brain of birds has neither the fame
ftructure nor the fame apparatus of folds,
eminences, and concavities, as that of man
and quadrupeds. The beautiful ftructure of
the eyes of thefe animals, their magnitude,
the thick and cartilaginous fclerotica, the
internal eye- lid, or membrana niffiitans, mov-
ed by peculiar mufcles, the mafs of the cryf-
talline and vitreous humours, the veflel of
black matter contained at the extremity of
the optic nerve, the brilliant colour of the
choroides, all denote a complicated organi-
zation, and a peculiar care taken by nature

to

ANIMAL FUNCTIONS. 277

to render the fight of birds penetrating; that
they may fee their prey at a great diftance,
and avoid the dangers which the rapidity of
their flight would otherwife have continu-
ally led them into; and, in a word, to pro-
mote that agility and quicknefs of motion,
which appear to be the lot of thefe animals.
Their fmell is lefs perfed: than their fight;
they do not appear to be very fenfible of the
fmell and tafte of food ; the fituation of the
apertures of the noftrils, and the hard mem-
brane which covers the beak, ferve to ex-
plain thefe phenomena with fufficient faci-
lity.

Among reptiles the fenfibility is not very
confiderable. The brain is very fmall, and
the nerves have no ganglions ; the fenfes, in
general, do not appear to be aftive, though
the eye, and internal ear, prefented a very
beautiful organization to Meffrs. Klein,
Geoffroy, and Vicq d'Azyr.

Fifties have a very fmall brain, and their
cranium is filled with an oily matter. Their
fenfes, more efpecially their fight and hear-
ing, are of confiderable delicacy. The or-
gan for the latter of thefe fenfes is very well
formed, as Meffrs. Klein, Geoffroy, Cam-
per, and Vicq d'Azyr have obferved. Such
naturalifts as have fuppofed fifties to be deaf,
appear therefore to be miftaken.

Infefts have no brain, but a lengthened
medullary fubftance, of a cylindric form,

S 3 full

278 ANIMAL FUNCTIONS.

full of nodules, which occupies the whole
length of their body. From this fubftance
iflue nervous fibres, which accompany the
divifion of the trachea. The eyes of in-.
fects are known. Swammerdam has de-
fcribed an optic nerve, which is divided in
fuch eyes as have the appearance of net-
work, into as many fibres as there are facets
in that membrane. It is not known whether
they have an organ of hearing.

Few or no traces of the fenfible organ are
perceived in worms. Swammerdam found
in the fnail a brain moveable and with two
lobes, eyes placed either on the bafe or
at the point of the tentacula, and an optic
nerve, contraftable like thofe kind of horns.
Mr. Adanfon affirms, that eyes are fome-
times either wanting in worms, or that they
are covered with an opake fkin.

As to polypi, they have no organ of fenfe,
though they appear to feek the light.

Senfibility is therefore a funftion enjoyed
by man in a much ftronger degree than by
other animals. It is this which diftinguifhes
him, and places him at the head of the ani-
mated creation ; and this fundion requires
to be carefully and minutely inquired into,
by the legiflator, the philofopher, and the
phyfician.

CHAP.

ANALYSIS. 279

CHAP. IX.

Concerning the Chemical Analyfis of Ani-
mal Subitances in general.

/TpHE analyfis of animal fubftances is a
■** part of chemiftry, which is the moft
difficult, and leaft advanced of any. The
ancient chemifts contented themfelves with
diftilling thefe fubftances by a naked fire;
an operation which is now known to alter,
and intirely change bodies of fo compounded
a nature as the folids and fluids of animals.
Some of the fluids of the human frame, and
of certain quadrupeds, only have been fub-
jedled to this analyfis.

Many caufes oppofe the advancement of
this branch of chemiftry; the difliculty and
unpleafantnefs of thefe experiments, the
fmall number of expedients for the treat-
ment of animal matters, without changing
them very much, the impofiibility of finding
the moft remote fynthetical method of re-
producing thefe matters, and more particu-
larly the uninterefting nature of thefe re-
fearches to chemifts who are not phyiicians,
are the principal motives which have hither-
to impeded the progrefs of fcience refpe&zng

S 4 them.

28o ANALYSIS OF

them. Neverthelefs, the refearches of cer-
tain modern philofophers, efpecially Meffrs.
Rouelle, Macquer, Bucquet, Poulletier de
la Salle, Berthollet, Prouft, Scheele, and
Bergman, have opened a new path, and fhew
that the art of healing may receive the great-
eft advantages from inquiries of this nature.
The bodies of the principal animals, fuch
as man and quadrupeds, to which cur at-
tention is particularly directed, are formed
of fluids and folids. The fluids of animals
are diftinguifhed into three clalTes, relative
to their ufes. The firit clafs contains the
recrementitial humours, defigned to nourifh
and fupport certain organs. The fecond com-
prehends the excrementitial humours which
are excluded out of the body, by certain
emunctories, as ufelefs, and capable of pro-
ducing noxious effects, if retained too long.
In the third are ranked, fuch as are of the
nature of the two preceding, being partly
recrementitial, and partly excrementitial :
the former are the blood, the lymph, the
jelly, the fibrous or glutinous part, the fat,
the marrow, the matter of internal perfo-
ration, and the offeous juice; the latter
comprehends the fluid of infenfible tranfpi-
ration, the fweat, the mucus of the noftrils,
the cerumen of the ears, the gummy mat-
ter of the eyes, the urine, and the feces.
Thefe laft are the faliva, the tears, the bile,
the pancreatic juice, the gaflric and intef-

tinaj

ANIMAL SUBSTANCES- 281

tinal juices, milk, and the feminal liquor.
We cannot examine all thefe fluids in the
order we have enumerated them ; 1 . Becaufe
they are very little known; 2. Becaufe it
is indifpenfably neceffary to treat of thofe,
in the firft place, whole analyfis is the moft
advanced.

The folids of animals, which form the
parenchyma of their different organs, may
be divided into three claffes ; the firft con-
taining foft and white parts, as the laminae
of the cellular tiffue, the membranes, the
membranous vifcera, the aponeurofes, the
ligaments, the tendons, and the fkin. The
foft and red parts form a fecond clafs, very
diftincT: from the firft -y fuch, in particular,
are the mufcles, and a part of thofe organs
which contain mufcular fibres, fuch as the
ftomach, the inteftines, the bladder, the ma-
trix, &c. Laftly, the third clafs compre-
hends the bony folids.

The animal analyfis is at prefent very dif-
ferent from that formerly ufed. The decom-
pofition by fire is now no longer praclifed,
and animal matters are treated with re-agents,
more efpecially acids, alkalis, fpirits of wine,
&c. The different fluids, mixed with each
other, or contained in the veficles of the
different parts, are feparated by repofe, by
decantation, by filtration, or by expref-
fion. The action of thefe fubftances on co-
louring matters is examined, as well as the

feveral

1?2 ASALYS1S OF

feveral changes they undergo at different
ten ires. By careful evaporation of

I liquors, the different (alts they con-
tai: panted without alteration.

By theft methods c Gs, modern che-

at diicoveries.
; difee rat Is different

from all thole b known. M. Berthol-

let taincd the exigence of difen-

gage /phoric acid in urine, and in iweat;

he has likewift found a very ccnliderahle
quantity of mephitis in
This I im-

port is j the

pre; fefubft. and

. explains the
dch e\ em and

To
cnlat flefli treated with

quantity is

>ut the : of

before

, and the : loft

be than jc ins to

; . M. Berthollet explai:
the formation erf bdi, afforded by

:~:ra tc :!on o{

fire. ::ion and i gc-

ment of :'/-■ (alt ther

:ion or re] mce of th<

ccs with ' . tters, which

putrefy,

ANIMAL SUBSTANCES. 283

putrefy, and afford volatile alkali by diflil-
lation. It appears, in fact, that this alkali
is formed, in both cafes, by the combina-
tion of inflammable gas with mephitis. I
cannot do better than quote, in this place,
the words of M. Berthollet on the general
nature of animal fub fiances, in a memoir
read at a public meeting of the Faculty of
Medicine, and inferted in the Journal de .
Phyfique, Vol. XXVIII. Page 272.

" Organized bodies are principally com-
" pofed of two fubflances, which have very
" evident diilin&ive charajfters : the one
" affords acid, when decompofed by the
" a&ion of fire, and the other volatile al-
" kali -, the one forms ardent fpirit, by fer-
" mentation, the other putrefies immedi-
" ately, and affords volatile alkali; the one,
" by calcination, affords a coal, which burns
<c readily, the other is reduced into a coal
t( of difficult combuflion : laftly, the for-
<c mer compofe the greatefl part of vege-
" table, and the latter of animal, fubflances;
" whence they are diflinguifhed by the two
" denominations.

" M. Bergman formed, by means of fugar
m and the nitrous acid, an acid which he
" called the faccharine acid, and which
" poffeffes remarkable properties. I applied
" this kind of analyfis by the nitrous acid
" to animal fubflances, and I found that
I* they all afforded a greater or lefs quantity

" of

284 ANALYSIS OF

" of faccharine acid, but always accompa-
" nied with a peculiar oil. I obferved that
" no ammoniacal fait was obtained, but
•' that a refidue was afforded, which is not
€e found in vegetables. From thefe firfl
" experiments I concluded (Memoires de
" l'Academie, 1780) that animal fubflances
«* contained a fubftance analogous to fugar,
*' united to an oil, which I confidered as
'* peculiar to animal fubftances. My ex-
" periments likewife informed me, that the
*c volatile alkali did not exifl in animal fub-
€t fiances, but that it arofe from a combi-
** nation formed either by the action of heat,
<c or the influence of putrefaction ; and
€C lailly, the refidue concerning which I
" did not explain myfelf in that memoir,
<c contains phofphoric acid in excefs, com-
" bined with calcareous earth.

" I afterwards examined the action of
V lime and metallic falts on animal fub-
€C fiances, and proved, that this action in
€€ which their cauflicity confifls, is a con-
" fequence of the chemical affinities of the
•* metallic calces, which tend with various
" degrees of force to become revived ; fo
*' that thofe which are very eafily revived,
tc fuch as the calces of filver and of mer-
" cury, have a flrong degree of cauflicity,
*' and form very cauflic falts. Hence
" it follows, by applying the modern dif-
" coveries of philofophers to the theory I

" have

ANIMAL SUBSTANCES. 285

have given, that it is the air combined in
metallic calces, and deprived of the prin-
ciple of elafticity, which tends to unite
with a principle of animal fubftances,
and this principle appears to me to be
the oil they contain ; but the caufticity
of alkalis cannot be attributed to the fame
caufe, but muft be the effedt of another
affinity. I have proved in the Memoirs
of the Academy for the year 1782, that
the cauftic alkali diffolved animal fub-
ftances without difuniting their princi-
ples. I have fhewn the properties of
this combination, and have availed myfelf
of it to unite the animal fubftances with
different metallic calces ; feveral combi-
nations were produced, which were be-
fore unknown to chemifts ; but the cauf-
tic alkali treated in the fame manner with
vegetable fubftances formed no combina-
tion. "

" By purfuing my inquiries, I have fuc-
ceeded in determining the principles of
the volatile alkali. I have fhewn, that
the volatile alkali is a combination of
detonating inflammable gas, or, to fpeak
more accurately, of the inflammable gas
of water and phlogifticated air, or me-
phitis : fo that the inflammable gas forms
nearly the fixth part of the weight, or
two-thirds of the volume of the volatile
alkali. I have fince determined how the

" volatile

286 ANALYSIS OF

" volatile alkali is produceable by putrcfao
" tion, or by the action of fire. All mat-,
" ters which have the character of animal
f< fubftances contain mephitis, which may
" be abundantly feparated by means of the
V nitrous acid. It mult neceffarily happen,
" therefore, when thefe fubftances are dif-
" tilled, that their mephitis mull pafs into
" fome combination, or that it will be found
" among the aeriform products -y but it is
" not found in thefe laft, as I have afcer-
ic tained, by detonating the inflammable gas
" obtained by this method in the eudiometer
" ofM. Volta, and comparing it with the
" inflammable gas obtained by the diftilla-
" tion of charcoal, and that of vegetable
" fubftances ; and there is nothing among
" the other products of the diftillation but
*? the volatile alkali, which can have re-
" ceived it into its compofition. Confe-
" quently, whenever v.olatile alkali is form-
" ed, the mephitis of the animal fubftances
" combines with the inflammable gas, which
" is feparated from the oil, or moft proba-
" bly with that which arifes from the de-
" compofition of the water, whofe vital air
" at the fame time combines with thechar-
" coal to form fixed air. In putrefaction,
M the inflammable gas combines with the
" mephitis; whereas in the fpirituous fer-
" mentation, the fame gas combines with
u a vegetable oil and fugar, to form fpirit

" of

ANIMAL SUBSTANCES. 287

* of wine, in which I have found and fepa-
? rated thefe fubftances, by means of the
f dephlogifticated marine acid.

" From thefe feveral obfervations it fol-
€ lows, that animal fubftances are much

* more compounded than fubftances which
' are purely vegetable. They contain a
f matter analogous to fugar, a peculiar oil,
f phofphoric acid combined with a fmall
' quantity of calcareous earth, mephitis,
1 and very probably fixed air. It is the

* phofphoric acid which exifts in the coal
1 of animal fubftances, combined with a
' portion of the true charcoal, of the oil,

* and with earth, that appears to me to
' conftitute the difference obferved to exift
c between the coals of animal fubftances

* and thofe of vegetables."

Such is the clear and perfpicuous manner
in which M. Berthoilet conceives and ex-
plains the general nature of animal fubftan-
ces. When thefe accurate refults are com-
pared with the vague notions hitherto exhi-
bited refpedting the difference between ve-
getable and animal matters, we are aftonifhed
at the progrefs which chemiftry has made of
late years, by the refearches of the Swedifh
and French chemifts. There is every reafon
to think, that a connected feries of inquiries
into the nature of animal matters, accor-
ding to the plan fketched out by the moft
celebrated chemifts from the time of Mar-

graaf

288 THE BLOOD.

graaf and Rouelle to the prefent, would af-
ford many valuable particulars of informa-
tion refpecting their formation, alterations,
and deftruftion ; and would be more parti-
cularly ufeful in the art of medicine. The
application of the difcoveries already made,
which we (hall exhibit in the following
chapters, will place this affertion beyond all
doubt.

CHAP. X.

Concerning the Blood.

/TpHE blood is the moll: important, the
•** moil compounded, and the moil impe-
netrable of the recreinentitious humours.
We ihall treat of it in the firffc place, be-
caufe, according to the doctrine of the greateft
phyficians, it is the fource and focus of all
the other animal fluids. Many phyficians,
and particularly Mr. Bordeu, confidered it
as a kind of fluid flefh, and as a compound
of all the animal humours. This opinion is
not intirely proved, though it is very pro-
bable.

The blood is a fluid of a beautiful red
colour, and an unctuous fat confidence, as it
were faponaceous, of an iniipid and rather

faline

THE BLOOD. 289

faline tafte, which is contained in the heart,
the arteries, and the veins. This fluid differs
greatly, according to the regions through
which it pafles ; it is not, for example, the
fame in the arteries, and in the veins, in
the ftomach, and in the region of the liver,
in the mufcles, and in the glands, &c.
This fadt has not been fufficiently attended
to by 'chemifts.

When we coniider the blood, with re-
fpec~t to the whole animal kingdom, we
may obferve that it varies remarkably in
different animals, with refpect to colour,
confidence, fmell, and more efpecially tem-
perature. This laft property is the moft
important, and appears to depend on the
circulation and the refpiration. The blood
of men, quadrupeds, and birds, is hotter
than that of the medium they inhabit; they
are therefore called animals with warm blood.
In fifties and reptiles it is nearly of the
temperature of the medium they inhabit ;
for which reafon they are called animals
with cold blood. It is probable, that dif-
ferences equally confiderable would be found
to obtain in all the other properties of this
fluid, and efpecially the chemical qualities
or characters, if the blood of all animals were
properly examined.

The blood of man, to which our attention
is particularly directed, diifers according to
the age, fex, temperament, and ftate of

Vol. IV. T health

2gO THE BLOOD.

health of the individual : in infancy, in
the female fex, and in confumptive perfons
it is paler, and thinner ; in robuft and
healthy men it is thicker, of a deeper co-
lour, almoft black, and of a much more
faline tafte.

Before we proceed to the analyfis of blood,
it will be proper to fpeak of its phyfical
properties ; namely its colour, temperature,
tafte, fmell, and peculiar confidence, which
we have already mentioned. The micro-
fcope difcovers a great number of globules,
which, when broken, according to Leu-
wenhoek and Boerhaave, by paffing through
the fmaller pafiages, lofe their red colour, be-
come yellow, and afterwards white -> fo that,
according to the phyfician of Leyden, a red
globule is an affemblage of many fmaller
white globules, and owes its colour to its
aggregation only. The blood likewife
prefents remarkable phyfical properties :
while hot, and in motion, it remains con-
ftantly fluid and red ; when it cools at reft
it takes the form of a folid mafs, which
gradually and fpontaneoufly feparates into
two parts ; the one red, which floats above,
whofe colour becomes deeper, and which
remains concrete, till it is altered by putre-
faction ; the other, which occupies the lower
part of the veffel, is of a yellow greenifh
colour, and adheiive : it is called ferum or
lymph. This coagulation and fpontaneous

feparation

1THE BLOOD. 2gt

feparation of the two parts of the blood takes
place at the laft moments of the life of the
animal, and produces thofe concrete fub-
flances which are found in the heart and the
large veffels, and have been falfly taken for
polypi. Blood expofed to a gentle heat long
continued, undergoes the putrid fermentation.
By diftillation on the water-bath, it affords
phlegm of a faint fmell, wrhich is neither
acid nor alkaline, but readily putrefies by
virtue of an animal fubftance it holds in fo-
lution. Blood heated more ftrongly, coa-
gulates, and gradually dries, as De Haen
has difcovered, loling feven-eighths of its
weight, and effervefcing with acids. By a
well managed fire, it hardens into a kind of
corneous fubftance. If dried blood be ex-
pofed to the air, it (lightly attracts humi-
dity, and at the end of fome months a faline
efflorefcence is formed, which Rouelle found
to be fait of foda. By diftillation with a
naked fire, it affords an alkaline and partly
acid phlegm ; that is to fay, in the ftate of
fal-ammoniac, fuper-faturated with alkali.
The nature of this empyreumatic acid, firft
perceived by Wieuffens, and which has ex-
cited fuch difputes among phyfiologifts, has
not yet been properly examined. A light
oil afterwards comes over ; next a coloured
and ponderous oil, and concrete volatile al-
kali, or ammoniacal chalk, contaminated by
the thick oil ; a fpungy coal remains in the
T 2 retort,

292 THE BLOOD.

retort, which is very difficult to incinerate,
and contains fea fait, cretaceous foda, iron,
and a fubftance apparently earthy, which is
found to be calcareous phofphate.

Blood united to alkalis becomes more fluid
by ftanding. Acids immediately coagulate
it, and change its colour. By filtration, and
evaporating of the filtrated liquor to drynefs
by a gentle fire, and fubfequent lixiviation
of this refidual matter, fuch neutral falts are
obtained, as fait of foda forms with each
acid ; any of which may be indifcriminately
uied. Spirit of wine coagulates blood.

Experiments made on blood in its original
ftate, do not fhew the nature of the fub-
ftances which compofe this fluid; but the
fpontaneous decompofition of blood, and the
feparation of its two parts, the clot and the
ferum, afford a method of performing this
by examining each fubftance in particular.
Till within a few years, the chemical ana-
lyfis of blood was confined to what has been
related in the foregoing pages. Meffrs.
Menghini, Rouelle the younger, and Buc-
quet, have examined this fluid in a very
different manner. They have made experi-
ments with this fubftance, which fhew how
nearly the analyiis of animal matters is ca-
pable of being brought to perfection by fol-
lowing their fteps. From the refearches of
thefe learned men, we fhall proceed to con-

fider

THE BLOOD. 293

fider the properties of each of the fubftances
which compofe blood.

The ferum, far from being pure water, is
a peculiar matter of great importance to be
confidered, and to which we give the name
of the albuminous fluid. It is of a yel-
lowifh white, inclining to green ; its tafte
is dull and faline ; its confidence undtuous
and adhefive. When expofed to heat, it coa-
gulates and hardens long before it boils. It
converts fyrup of violets to a green. When
diftilled on the water-bath, it affords a mild
and infipid phlegm, neither acid nor alka-
line, but fubjedt to putrefaction : the matter
in the retort is then dry, hard, and transpa-
rent like horn, and no longer foluble in
water ; but by a ftrong heat it affords an
alkaline phlegm, much concrete volatile al-
kali, and a very fetid oil. All thefe pro-
ducts in general have a peculiar fetid fmell.
The coal of ferum diftilled by a naked fire,
almoft intirely fills the retort. It is fo diffi-
cult to incinerate, that it requires to be
kept red hot for feveral hours, with a large
furface expofed to the air, before it can be
reduced to afhes. The afhes are of a blackifh
grey, and contain marine fait, chalk of foda,
and calcareous phofphate.

Serum expofed for a certain time to a

warm temperature in an open vefTel, partes

quickly to putrefaction, and then affords

much concrete volatile alkali of an abomi-

T 3 nable

294 THE BLOOD.

liable fmell. It putrefies fo rapidly, that
Bucquet could not decide whether it pafles
to acidity before it becomes alkaline. This
fluid unites with water in all proportions,
and then lofes its confiftence, its tafte, and
its greenifh colour -> the mixture muft be
agitated, in order to promote the union of
the two fluids, which are kept apart by their
different denfities. Serum poured into boil-
ing water, for the moft part coagulates in-
ftantly. A portion of this fluid forms with
water a kind of white, opake, and milky
fluid, which, according to Bucquet, has all
the characters of milk ; that is to fay, it
affords cream, coagulates by heat, by acids,
&c.

Alkalis added to ferum, render it more
fluid by a kind of folution. Acids change it
in an oppolite manner, by giving it con-
fiftence, and by coagulating it. This laft
mixture being filtrated, and the fluid eva-
porated, the neutral fait which the acid
made ufe of forms with foda, is obtained ;
which proves, that this laft fait exifted in a
difengaged ftate, and poffefled of all its pro-
perties, in the ferum. The coagulation form-
ed in this liquor by the addition of an acid,
diflblves very quickly in volatile alkali,
which is the true folvent of the albuminous
part ; but it i$ not all foluble in pure water.
Acids precipitate this fubftance united to
the volatile alkali. The coagulation diftilled

by

THE BLOOD. 295

by a naked fire affords the fame products as
dried ferum, and its coal contains much
cretaceous foda ; which proves, according
to Bucquet, that there is a portion of this
fait fo intimately combined in the ferum,
as not to be faturated by the coagulating
acid.

The ferum, in its denfe ftate, affords me-
phitis by the action of the nitrous acid on
the application of a gentle heat. If the heat
be raifed, nitrous gas is difengaged from the
mixture; the refidue affords the acid of fu-
gar, and likewife a fmall quantity of the
peculiar acid, called malufian acid, byM. de
Morveau. (See the Preliminary Differtation
at the commencement of our firft volume,
page lxxxviii).

Serum does not decompofe the calcareous
and argillaceous neutral falts; but it decom-
pofes metallic falts very readily, It is coa-
gulable by fpirit of wine, and this coagula-
tion differs greatly from that which is formed
by acids, more particularly in its folubility
in water, as Bucquet has difcovered. This
liquid therefore appears, from thefe experi-
ments, to be an animal mucilage compofed
of water, acidifiable oily bafes, marine fait,
chalk of foda, and calcareous phofphate ;
this laft appears to produce the rofe-coloured
precipitate, which I have obtained by pour-
ing the nitrous folution of mercury into fe-
rum. Though the liquid be fcarcely coloured,
T 4 the

296 THE BLOOD.

the addition of nitrous acid, and more efpe-
cially of mercurial nitre, produces a rofe
or light flefh colour, which I have fre-
quently obferved in many other animal li-
quors. The moft Angular property of this
mucilage, which deferves the attention of
phyficians is, its becoming concrete by the
action of fire, and of acids. Mr. Scheele
thinks that this phenomenon arifes from the
combination of heat.

The clot of blood expofed to the heat of
a water-bath, affords an infipid water, and
becomes dry and brittle. By diftillation it
affords an alkaline phlegm, a thick oil of a
fetid and empyreumatic fmell, and much
volatile alkali. Its refidue is a fpungy coal
of a brilliant and metallic afpect, difficult to
incinerate, and which when heated with the
vitriolic acid affords vitriols of foda and of
iron. After thefe operations, a mixture of
calcareous phofphate and coaly matter re-
mains. The clot of blood putrefies very
quickly in warm air. When warned with
water, it is feparated into two very diftincl:
fubftances, one of which is diiTolved, gives
the fluid a red colour, and the folution,when
heated with different menftrua, exhibits all
the characters of ferum -, but it contains a
much greater quantity of iron, which may
be obtained by incineration of the coal, and
fubfequent warning, to feparate the faline
matters. The refidue of this warning is

faffron

THE BLOOD. 297

faffron of Mars, of a beautiful colour, and
ufually attra&ed by the magnet. The co-
lour of blood is attributed to this metal.
Iron has been obtained from blood in confi-
derable quantities, by Menghini, Rouelle,
and Bucquet.

The clot, after having been wafhed, and
deprived of all its red ferum, appears to con-
fift of a white fibrous matter, which remains
to be examined.

The fibrous part of the blood is white,
colourlefs, and infipid, after it has been
well wafhed. By diftillation on the wa-
ter-bath, it affords a taftelefs phlegm of
a faint fmell, and capable of putrefaction.
The moft gentle heat Angularly hardens the
fibrous matter : when fuddenly expofed to
a ftrong heat, it fhrinks up like parchment.
By diftillation in a retort, it affords an alka-
line phlegm, a ponderous, thick, and very
fetid oil, with much amnion iacal chalk con-
taminated by a portion of oil. Its coal is not
bulky, but compact and heavy, and is lefs
difficult to incinerate than that of the lymph.
Its afhes are very white, and contain neither
faline matter nor iron; which doubtlefs were
carried off by the previous wafhing : the ap-
pearance of thefe afhes is earthy, and they
feem to confift of calcareous phofphate.

The fibrous part in the blood putrefies
very quickly, and with great facility ; when
expofed to a hot and moid air, it fvvells,

and

29% THE BLOOD.

and affords much volatile alkali. It is not
foluble in water ; when boiled with that
fluid it hardens and affumes a grey colour.
Alkalis do not diffolve it ; the moft feeble
acids combine with it. The nitrous acid
difengages much mephitis, as Mr. Berthol-
let has obferved, and afterwards diffolves it
with effervefcence, and difengagement of ni-
trous gas ; when fill this gas is difengaged,
oily and faline flocks are obferved in the re-
sidue, which float in a yellowifh liquor ; by
evaporating this liquor cryftals are obtained,
analogous to the acid of fugar, or oxaline
acid (fee the Additions to the Vegetable
Kingdom), and a conflderable quantity of
flocks formed of a peculiar oil and calcare-
ous phofphate is depofited. There feem to
be two oils in the fibrous part ; one, which,
with the oxyginous principle, constitutes
the oxaline acid ; the other, which with the
fame principle, forms the malufian acid.

The fibrous matter is likewife foluble in
the muriatic acid, which caufes it to affume
the form of a green gelly. The acid of vine-
gar diffolves it with the afliftance of heat :
water, and more particularly alkalis, preci-
pitate the fibrous matter when diffblved in
acids. This animal fubftance is decompofed
in thefe combinations , and when feparated
from the acids by any method, it no longer
prefents the fame properties.

The neutral falts, and other mineral fub-

flances,

THE BLOOD,

*99

ftances, do not adt upon it. It unites to the
lymph, efpecially that which is coloured,
to form the clot. This laft, like the fibrous
part, is totally foluble in acids ; doubtlefs,
on account of the combination of this mat-
ter with the red ferum. Hence we fee, that
the fibrous part differs greatly from the al-
buminous matter. It is a fubftance more
perfectly animalized than this laft ; a kind
of animal gluten, which greatly refembles
that of flour j and which more efpecially
poffefles the remarkable property of be-
coming concrete, by cooling and reft. It
cannot be doubted, but that this matter,
which has not hitherto been diftin&ly ob-
ferved by phyfiological and pathological phy-
ficians, is of the greateft confequence in the
animal economy. I have long fince ob-
ferved, that it is depolited in the mufcles,
conftituting the fibrous bafe of thefe organs,
and that it forms the fubftance which is moft
eminently irritable. Whence I have inferred,
that it is of confequence to pay a greater
attention to this fubftance than has hitherto
been done ; and to confider it as capable by
its abundance or deviation of caufing pecu-
liar diforders. And I have exhibited the
proofs of thefe ufeful medical confiderations
in a Memoir, which will be inferted in the
volume of the Royal Society of Medicine for
the year 1783, &c.

Notwithstanding thefe refearches into the

nature

300 ,a> MILK.

into the nature of blood, much remains to
be done before its chemical properties will
be perfectly known. The intimate differ-
ence between the ferum and the fibrous part
is yet unknown : neither has blood been yet
examined in all its ftates ; efpecially in the
different diforders which confiderably alter
this fluid ; as for example, in ftrong inflam-
mations, in the chlorofis, fcorbutic diforders,
&c. Phyficians judge of thefe alterations
merely by the external appearance, and it is
much to be wifhed that their nature were
better afcertained by accurate analyfis.

Rouelle has examined the blood of feveral
quadrupeds, fuch as the ox, the horfe, the
calf, the fheep, the hog, the afs, and the
goat ; he obtained the fame products as from
the human blood, but in different propor-
tions.

CHAP. XI.

Concerning Milk.

TV/TILK is a recrementitial humour de-
figned to nourifh young animals in the
early part of their life. It is of an opake
white colour, a mild faccharine tafte, and
a flightly aromatic fmell. It is feparated

immediately

MILK.

30I

immediately from the blood in the breads
or udders of the female animals, to which
it is conveyed principally by the arterial
mammariae. Man, quadrupeds, and ceta-
ceous animals, are the only creatures which
afford milk. All other animals are defti-
tute of the organs which fecrete this fluid.

Milk differs greatly in the feveral animals ;
in the human fpecies it is very fweet or fac-
charine ; the milk of the cow is mild, and
its principles are well connected -y that of the
goat and afs have a peculiar virtue, as they
are often flightly aftringent. The variable
properties of milk depend ufually on the
food of the animal.

Cows milk, which is taken as an example
of the analyiis, becaufe it is eafily procured,
is a compound of three different fubftances,
ierum, or whey, which is fluid and tranfpa-
rent ; butter and cheefe, which are more
confident. Thefe three parts are fo mixed
as to form a kind of animal emulfion.

Milk diftilled by the heat of a water-bath,
affords a taftelefs phlegm of a faint fmell,
and capable of putrefaction. By a degree of
heat fomewhat ftronger, it coagulates like
the blood, according to the obfervation of
Bucquet ; by agitation, and gradual dry-
ing, it forms a kind of faccharine extradr,
called franchipane. This extract, diffolved
in water, constitutes the whey of Hoffman -y
the extract diftilled by a naked fire affords

acid,

302

MILK,

acid, fluid oil, concrete oil, and ammonia-
cal chalk. Its coal contains a fmall quan-
tity of vegetable alkali, febrifuge fait, and
calcareous phofphate.

Milk, when expofed to a hot temperature,
is capable of undergoing the fpirituous fer-
mentation, and forming a kind of wine; but
it isneceiTary that the'quantityfhould be large.
The Tartars prepare a fpirituous liquor with
mares milk. Milk quickly becomes acid,
and coagulates. The cafeous part becomes
folid, and the ferum feparates.

Acids immediately produce the fame ef-
fects on milk -, they coagulate it, but alkalis*
more efpecially the volatile alkali, re-dif-
folve this coagulum. Boerhaave affirms,
that milk, when boiled with oil of tartar,
becomes firft yellow, afterwards red, and of
the colour of blood. He even thinks, that
it is a fimilar combination, which caufes the
milk to be converted into true blood in the
human body. Neutral falts, fugar, and gum,
likewife coagulate milk by the afiiftance of
heat, according to the obfervation of Scheele.

To prepare whey, milk is heated, and
twelve or fifteen grains of rennet is added to
every pint. This fubftance, formed by the
mixture of milk, turned four in the fto-
mach of calves, and of the gaftric juice, is
a ferment which coagulates the cafeous
part. When the coagulation is made, the
whey is {trained from the curd. Gallium,

the

MILK. 303

the flowers of the thiftle, and of artichoke,
ad: in the fame manner as rennet upon milk.
The internal membrane of the ftomach of
calves, and of birds, dried and pulverized,
produces the fame effecT: upon milk ; which
proves that the coagulation is produced by
the gaftric juice, dried and contained in the
pores of this membrane.

Serum, or whey, prepared in this manner,
is turbid ; it may be clarified by white of egg,
or cream of tartar. When the ferum, or whey,
is required to be very pure, for the pur-
pofe of examining its nature, cream of tartar
muft not be added.

Whey has a mild tafte. When prepared
with new milk, it contains a faccharine ef-
fential fait, but it foon acquires an acid tafte,
by the eitabliftiment of the acid fermenta-
tion. This change is produced by the al-
teration of a mucilaginous principle, con-
tained in the milk; and it is the develope-
ment of this acid which occafions the fpon-
taneous feparation of the whey from the
other fubftances contained in milk. It is
therefore neceffary to examine the acid,
which is formed in milk, and conftitutes
fermented whey. It is a well known fa£t,
that milk left expofed in a temperature of
feventy or eighty degrees, experiences, in a
few days, a fermentation which developes
an acid, and feparates the butter and cheefe.
The acid, formed by this fermentation, and

which

304 MILK.

which is as ftrong as it will be at the end
of twelve or fifteen days, has been examined
by Mr. Scheele, and is called the gala<ftic
acid by M. de Morveau. The following is
the procefs uied by Scheele, to obtain it in
a ftate of purity. After having attempted,
in vain, to feparate the acid by diflillation
from four whey, by which he obtained only
a fmall quantity of vinegar, he evaporated
the whey to one eighth, after having fil-
trated it, to feparate all the cafeous mat-
ter. From this he precipitated the animal
earth, by lime-water. He then diluted the
fluid with three times its weight of water,
and feparated the lime by the acid of fugar ;
at the fame time taking care that this laft
acid mould not remain difengaged in the
folution, which was eafily afcertained and
prevented, by the addition of fuccefiive fmall
portions of lime-water. The fugar of milk,
and feveral other foreign fubftances, were
then feparated, by the addition of fpirit of
wine, which eafily difiblves the acid of milk.
Laftly, the decanted folution being diftilled,
the fpirit of wine paused over, and the pure
galadtic acid remained in the retort. Scheele
has obferved the following properties in this
acid.

When ftrongly evaporated, it did not af-
ford cryftals, but attracted the humidity of
the air : by diftillation, it afforded an em-
pyreumatic acid, refembling fpirit of tartar;

a fmall

MILK. 305

a fmall quantity of oil, and a mixture of
cretaceous acid and inflammable gas.

With the three alkalis, and alfo with pon-
derous earth and lime, it forms deliquefcent
falts. Its combination with magneiia cryf-
tallizes, but likewifc attracts the moifture
of the air. It does not at all attack cobalt,
bifmuth, antimony, mercury, filver, or
gold, even by the heat of ebullition. It
diflblves zink and iron, producing inflam-
mable gas ; the firft of thefe falts, called by
Morveau the galadte of zink, cryftallizes ;
the fecond, or the galadte of iron, forms
a brown deliquefcent mafs. The galactic
acid calcines, and diflblves copper and lead.
The galactic folution of the latter metal
depoflts a fmall quantity of vitriol of lead,
which indicates the prefence of a fmall
quantity of vitriolic acid in this animal
acid. Laftly, it decompofes the acetous fait
of pot-afh ; a property which, together with
moft of thofe here mentioned, denotes, as
M. de Morveau obferves, that the galactic
acid differs from vinegar. M. Scheele adds,
likewife, that a true vinegar may be obtain-
ed from milk, by mixing fix fpoonfuls of
fpirit of wine with three pints of milk, and
fuffering the mixture to ferment in a well-
clofed veflel. The gas, which is difen-
gaged during this fermentation, muft be
furfered to efcape, from time to time; and
at the end of a month the milk is changed

Vol. IV. U into

306 MILK.

into good vinegar, which may be {trained
through a cloth, and preferved in bottles.
This celebrated Swedifh chemift likewife
adds, that milk, in a bottle whofe neck is
plunged in a veffel rilled with the fame li-
quor, and expofed to a heat fomewhat
ftronger than that of fummer, undergoes a
fermentation which affords a large quan-
tity of elaftic fluid. This laft fluid difplaces
the milk, and almoft intirely empties the
bottle, at the end of two days. The acid pro-
duced in this fermentation, which takes
place without the contact of air, appears to
receive its oxyginous principle, or acidifying
bafe of the air, from the decompolitiori of
the water.

The ferum of milk, or whey, made by
means of rennet, and not yet become four,
holds in folution a certain quantity of a fa-
line fubftance, known by the name of fait,
or fugar of milk. Though Kempfer affirms
that the Brachmans were acquainted with
the procefs for preparing this fait, it ap-
pears that it was rlrft mentioned by Fabri-
cius Bartholet, or Bartholdi, an Italian phy-
lician, in the year 1619. Etmuller, Tefti
Werlofchnigg, Wallifnieri, Fickius, andCar-
theuler, have fucceffively fpoken of this fub-
ftance, and defcribed the methods of obtain-
ing it. Meffrs. Vulgamoz and Lichtenftein
have very well defcribed the method of ob-
taining this faline fubftance, which is pre-
pared

MILK. 307

pared in large quantities in feveral parts of
Switzerland. The whey obtained from
ikimmed milk, coagulated with rennet, is
evaporated to the confiftence of honey ; after
which it is put into moulds, and dried in
the fun. This is the fugar of milk in cakes,
and is diffolved in water, clarified with whites
of eggs, evaporated to the confiftence of fy-
rup, and cryftallized in the cold. By this treat-
ment it affords white cryftals, in rhomboidal
parallelipipedons ; the mother water depofits
yellow and brown cryftals, which are purified
by fuccefiive folutions. Mr. Lichtenftein has
examined and analyzed the different fugars of
milk, which are fold at various prices in Swit-
zerland, and has more particularly diftin-
guifhed, 1 . The fweet fugar of milk, which
is of a white colour, obtained from fweet
and purified whey. 2. The acefcent fugar
of milk, obtained from four whey. 3. The
fugar of milk, rendered impure by fat fub-
ftances ; which feparate, according to him,
in the firft cryftallization. 4. Sugar of milk,
mixed with oil and common fait, which
cryftallizes the laft. 5. Sugar of milk, mix-
ed with fat matter, common fait, and fal-
ammoniac. It is adhefive and moift, and
affords volatile alkali on the addition of fixed
alkali. 6, And laftly, Sugar of milk, mixed
with all the before-mentioned fubftances, and
likewife with extractive and cafeous matter*

U 2 This

308 MILK.

This laft is of the confidence of honey, be-
comes rancid, and is acrid and difagreeable.

Sugar of milk, when very pure, has a
(lightly faccharine, faint, and as it were
earthy tafte ; it always lofes by fucceffive fo-
lutions. It is foluble in three or four parts
of boiling water ; and, according to Scheele,
Rouelle, and Vulgamoz, it affords the fame
products as fugar by diftillation. Rouelle
obtained from a pound of this fait, by burn-
ing it, 24 or 30 grains of afhes ; three-
fourths of which were febrifuge fait, or
muriate of pot-am, and one-fourth chalk of
pot-am, or mild vegetable alkali. On a red-
hot coal, fugar of milk melts, boils up, emits
an odour of caramel, and burns like fugar.
Thefe properties appear to indicate, that this
fait is capable of affording the acid of fugar -,
and Mr. Scheele has fhewn, by his experi-
ments, that it does : but he obferved, that
a large quantity of fpirit of nitre is required
for this purpofe ; that four ounces of fugar
of milk afford five grains of faccharine acid j
and he has alfo difcovered, that if the refidues
of fugar of milk be treated by the nitrous acid,
and filtrated, in order to cryftaliize the fac-
charine acid by evaporation, a white powder
remains on the filter -y which he found to
be a peculiar acid, and named it the acid of
fugar of milk. He obferved, that it pof-
fefles the following properties.

It has the form of a white granulated

powder ;

MILK. 309

powder ; two drachms of this fait, very pure,
being heated in a glafs retort, melted, fwell-
ed up, and became black; a brown fait, of
a mixed fmell of benzoin and amber, fub-
limed, weighing 35 grains ; this fait was
acid, foluble in fpirit of wine, more diffi-
cultly in water, and burned on charcoal.
The receiver contained a liquor of a brown
colour, and not of an oily nature 5 eleven
grains of charcoal remained in the retort.
Cretaceous acid and inflammable gas were
difengaged during this diftillation. The
acid of fugar of milk is very fparingly fo-
luble in water, one ounce of boiling water
diffolving only fix grains ; one-fourth of
which was precipitated by cooling. Ac-
cording to M. de Morveau, this acid effer-
vefces with the hot folution of cretaceous
vegetable alkali. A cryftallized fait was ob-
tained, by cooling, which was foluble in
eight times its weight of hot water, and cryf-
tallized again by cooling. The fait it formed
with the mineral alkali was cryftallizable, but
required no more than five parts of water for
its folution. This acid combines likewife
with the volatile alkali; the neutral fait,
thus produced, lofes its alkali by heat. With
ponderous earth, clay, magneiia, and lime,
it forms falts, nearly infoluble. It acts but
very feebly on the metals, and forms with
their calces falts of difficult folubility. It
U 3 pre-

3io

MILK

precipitates the nitres of mercury, lead, and
iilver, as well as the muriate of lead.

Mr. Scheele, when he fir ft made this dif-
covery, fuppofed that the white powder, de-
pofited by the faccharine acid obtained from
fugar of milk by means of the nitrous acid,
was merely a proportion of the calcareous
fait, formed by the faccharine acid and a
proportion of the lime, which might be
contained in that animal fait. But he was
foon undeceived, by pouring a fmall quan-
tity of faccharine acid into a folution of fu-
gar of milk ; as the mixture afforded no pre-
cipitate. Neverthelefs, Mr. Hermftadt, who
has published two memoirs in Crell's Che-
mical Journal, the fecond of which treats
particularly of this acid earth, thinks, not-
withstanding the experiments of Scheele,
that it is a compound of faccharine acid, cal-
careous earth, and a fat fubftance. But M.
de Morveau, after examining the experi-
ments of this chemift, with his ufualaccu-
racy, and comparing them with thofe of
Scheele, has fhewn, in the new Didtionaire
Encyclopedique, that Mr. Hermftadt has
not accomplished his undertaking, and that,
even from his own remits, the difcovery of
the Swedifh chemift is rather confirmed than
deftroyed. M. de Morveau has like wife
made feveral ingenious experiments which
confirm this after tion. To thefe accounts
we may add, that the acids of milk, and of

fugar

MILK. 3U

fugar of milk, do not exift ready formed in
fugar of milk, and that this fait contains
only the bafes, which take the oxyginous
or acidifying principle from the nitrous
acid. We may likewife obferve, that fubfe-
quent experiments will probably (hew, that
the acid of fugar of milk is nothing more
than a modification of fome other vegetable
acid ; for every circumftance tends to prove,
that the principles of whey are derived from
the vegetables on which the animals fubfift.

The Baron de Haller has given the fol-
lowing proportions of the fugar contained in
the milk of different animals.

Four ounces of fheep's milk, afforded of

Sugar of milk - 35 or 37 grains.

Goat's milk afforded 47 — 49

Cow's milk - - 53 — 54

Human milk - 57 — 58

Mare's milk - - 69 — 70

Afs's milk - - 80 — 82

Rouelle has obferved, that the whey of
cow's milk, from which the fugar of milk
has been extracted, takes the form of jelly
by cooling j and he confequently admits it
to contain gelatinous matter.

Cheefe, or the cafeous matter, takes the
folid form, and is feparated from the other
conftituent parts of milk, by the a&ion of
fire, by the acid fermentation, and by the
mixture of acids. This matter, when well

U 4 wafhed,

312 MILKU 9,

wafhed, is white, folid, and as it were fi-
brous ; the a&ion of a gentle heat hardens
it. Diftillation oft a water-bath extracts an
infipid phlegm, which putrefies.

Dried cheefe, diftilled in a retort, affords
an alkaline phlegm, a ponderous oil, and
much concrete volatile alkali. Its coal is
denfe, very difficultly incinerated, and does
not afford fixed alkali. When this coal is
treated with nitrous acid, it is found to con-
tain lime, and the phofphoric acid.

Cheefe putrefies in a hot temperature; it
fwells, emits a naufeous fmell, becomes im-
perfectly fluid, and is covered with a fcum, or
froth, arifing from the difengagement of a
very ftrong-fmelling and mephiticgas, which
efcapes with difficulty from this vifcid mat-
ter.

Cheefe is infoluble in cold water; hot
water hardens it. Mr. Scheele has obferved,
that when it has been precipitated by a fo-
reign acid, boiling water diffolves a part.

Alkalis diffolve it, more particularly the
volatile alkali, which, when poured in the
quantity of a few drops into milk coagu-
lated by an acid, caufes the coagulum quick-
ly to difappear.

The concentrated acids likewife diffolve
cheefe; fpirit of nitre difengages mephitis;
but the vegetable acids do not fenfibly diffolve
It. Its folution in the mineral acids is precipi-
tated

MILK. 313

tated by the alkalis, which rediflblve it if
added in too great a quantity.

The neutral falts, more particularly ma-
rine fait, retard its putrefaction.

From all thefe fafts it appear^, that cheefe
is a fubftance greatly refembling lymph ; but
as it is not itfelf foluble in water, it is ori-
ginally fufpended in milk, by virtue of the
gelatinous mucilage, and the extractive and
faccharine fubflances contained in that fluid.

Butter is partly feparated from milk by
reft : it is collected at the furface, but as
it is mixed with much ferum, and cafeous
matter, it is more completely feparated by
ftrong agitation, in which the art of making
butter confifts. The ferum, from which
butter is feparated by agitation, retains a
portion of this oily fubftance, and is yellow,
four, and fat ; it is called butter-milk.
Cream is a mixture of cheefe and butter,
which is fkimmed off the furface of milk
that has ftood for fome time. It is much
more difficult of digeftion than milk itfelf.
If cream be ftrongly agitated, it takes the
form of froth, and is then called whipt
cream.

Pure butter is concrete and foft, of a
yellow colour, approaching more or lefs to
that of gold, and of a mild agreeable tafte.
It melts by a gentle heat, and becomes folid
by cooling. When diftilled on a water-
bath, it affords a phlegm nearly infipid. By

a ftronger

314 MILK.

a fironger heat, it affords a very penetrating
and flrong acid, a fluid oil, and afterwards
a concrete coloured oil, of the fame pene-
trating fmell as the acid. By reftifying
thefe product?, the oil is rendered as fluid
and volatile as effential oils. The remaining
coal is not abundant. The acid obtained
from butter, by diftillation, feems to be of
the fame nature as that of fat, which we
fhall hereafter mention by the name of the
febaceous acid. It may likewife be ob-
tained in the ftate of neutral falts, by the
addition of lime or the fixed alkalis.

Butter foon becomes four and rancid in a
hot air. Its acid is then developed, and its
tafte is difagreeable. Water, and fpirit of
wine, in fome meafure reftore its original
tafte, by dirTolving the acid. The fixed al-
kalis diffolve butter, and form a kind of
foap, which is little known.

Hence we find, that butter is an oily fub-
ftance, of the nature of the fat vegetable
concrete oils.

Frefh butter is mild, temperate, and re-
laxing. But it readily becomes four, and
in general agrees with few ftomachs. Rancid
butter, whofe acid is developed, is one of
the mod unwholfome and indigeftible of
all foods.

Milk is an agreeable food, of confiderable
ufe in a great number of cafes ; it is even
one of the moft valuable medicines we pof-

fefs.

MILK. 3T5

fefs. It correfts the acrid humours in dis-
orders of the fkin, and of the articulations.
It cicatrices ulcers of a good kind. It may-
be charged with the aromatic parts of plants,
and is then an excellent remedy in the pul-
monary confumption. All ftomachs, how-
ever, do not digeft milk. Such perfons as
are inclined to acidities in the firft paffages,
are ufually incommoded by it; and in general
it ought to be adminiftered prudently. Milk,
rendered medicinal, by caufing the animal
which gives it to take different fubftances,
is often ufed with fuccefs in various diforders.

The milk of different animals have cer-
tain peculiar virtues ; that of the human
fpecies is mild, of a faccharine tafte, and is
greatly ferviceable in the marafmus. The
milk of the afs is fuccefsfully ufed in the
pulmonary confumption, and the gout : it
ufually relaxes. Mare's milk refembles that
of the afs. Goat's milk is ferous, and lightly
aftringent. Cow's milk is the thickeft, the
fatteft, and the moll nourifhing ; it is like-
wife the moft difficult of digeftion, and often
requires to be diluted with water, or with
fome aromatic infufion, efpecially if it does
not eafily pafs off, or produces coftivenefs.

Milk is like wife ufed externally, as a foft-
eni.ng and emollient remedy. It mitigates
pain, ripens gatherings and abfceffes, and
haftens fuppuration. It is applied hot, and
inclofed in a bladder on the difeafed parts.

CHAP.

3l6 FAT.

CHAP. XII.

Concerning Fat.

T? AT is a concrete oily matter, contained
-* in the cellular membrane of animals;
it is white, or yellowifh, with little or no
fmell or tafte, and differs in all animals in
its folidity, colour, tafte, &c. and likewife
in the fame animal, at different ages. In
infancy it is white, infipid, and not very
folid ; in the adult it is firm, and yellowifh ;
and in animals of an advanced age, its colour
is deeper, its confidence various, and its
tafte in general ftronger. The fat of man,
and of quadrupeds, is confiftent, white, or
yellow. That of birds is finer, fweeter, more
undluous, and in general lefs folid. In
cetaceous animals and fifties, it is almoft
fluid, and frequently placed in peculiar re-
fervoirs, as in the cavity of the cranium. It
is likewife found in ferpents, infects, and
worms ; but in thefe animals it is only met
with among the vifcera of the lower belly,
on which it is placed in feparate portions ;
being fcarcely ever obferved but in minute
quantities, on the mufcles or beneath the
flcin.

It

FAT. 3I7

It has been obferved, that the fat of fru-
givorous and herbivorous animals is firm and
folid, while that of carnivorous animals is
more or lefs fluid. It muft, however, be re-
marked, that the fat is always lefs folid and
concrete, in the warm and living animal,
than in the fame animal when dead and cold,
in the hands of the diffedtor.

Fats vary, according to the parts of the
animal from which they were taken : it is
folid near the reins, and beneath the fkin ;
it is lefs firm between the mufcular fibres,
or near moveable vifcera, fuch as the heart,
the ftomach, and the inteftines. It is more
abundant in winter than in fummer ; it ap-
pears deftined to maintain the heat in thofe
regions wherein it is placed, as many facts,
collected by phyfiologifts, demonftrate. It
even appears to contribute to the nourifh-
ment of animals, as is obfervable in bears,
the mountain rat, the dormoufe, &c. and
in general all animals, forced to Ion? abfti-
nence, in which the fat melts, and gradually
difappears.

To prepare fat for pharmaceutical purpofes,
it muft be cut in pieces, and the membranes
and veffels feparated ; it is afterwards to be
wafhed with much water, and melted in a
new earthen veffel, with the addition of a fmall
quantity of water; when this fluid is difli-
pated, and the ebullition ceafes, it muft be

poured

31? *AT.

poured into a glazed earthen vefTel, where
it fixes, and becomes folid.

Fat has not yet been examined fufficiently
to afcertain all its chemical properties. The
action of fire, air, and certain menftruums,
on this fubftance, only are known. It is
neverthelefs highly neceflary to be perfe&ly
acquainted with this animal fubftance, in
order to judge of its ufes -, concerning which
nothing is yet certainly known, and more
especially the alterations it is fubject to in
living bodies.

The fat of any animal, expofed to a gentle
heat, liquifies, and congeals by cooling. If
it be ftrongly heated, with contact of air, it
emits a fmoke of a penetrating fmell, which
excites tears and coughing, and takes fire
when fufficiently heated to be volatilized :
the charcoal it affords is not abundant. If
fat be diftilled on a water-bath, an infipid
water of a flight animal fmell, is obtained,
which is neither acid nor alkaline, but which
foon acquires a putrid fmell, and depofits
filaments of a mucilaginous nature. This
phenomenon, which takes place with the
water obtained by diflillation on the water-
bath, from any animal fubftance, proves,
that this fluid carries up with it a mucila-
ginous principle, which is the caufe of its
alteration. Fat, diftilled in a retort, affords
phlegm, at firft aqueous, and afterwards
ftrongly acid y an oil, partly liquid, and

partly

FAT. 319

partly concrete ; a very fmall quantity of
charcoal, exceedingly difficult to incinerate,
in which Mr. Crell found a fmall quantity
of calcareous phofphate. Thefe products
have an acid and penetrating fmell, as ftrong
as that of the fulphureous acid. The acid
is of a peculiar nature, and has been care-
fully examined by Mr. Crell ; but as it is
very difficult to obtain by diftillation, this
celebrated chemift has ufed a much more
certain and expeditious procefs, which we
fhall prefently defcribe. The concrete oil
may be rectified, by repeated diftillation, fo
as to become very fluid, volatile, and pene-
trating , in a woi*d, to prefent all the cha-
racters of a true effential oil. Twenty-eight
ounces of human fat afforded Mr. Crell
twenty ounces five drachms forty grains of
fluid oil, three ounces three drachms and
thirty grains of febaceous acid, three ounces
one drachm four grains of a brilliant char-
coal, confiderably refembling plumbago, as
M. de Morveau remarks. Five drachms fix
grains of matter were loft in this analyfis,
which may be attributed to the water in
vapour, and the elaftic fluids, becaufe Mr.
Crell did not ufe the pneumato-chemical
apparatus.

Fat expofed to a hot air, alters very
quickly; the mild,' and fcarcely fenfible
fmell, is changed to ftrong rancidity. This
alteration appears to confift of a true fer-
mentation,

320 FAT.

mentation, by which the acid is developed
and difengaged. Though this acid appears
to be of the nature of the febaceous acid,
yet I cannot think that the oily part of the
fat is the fole caufe of the change, but that
the peculiar animal mucilage, which fubfe-
quent analyfis will difcover, has alfo a
fhare in it. Pvancid fat may be corrected
by two methods : water is capable of carry-
ing off the acid it contains, as Mr. Poerner
has obferved ; fpirit of wine has the fame
property, according to Mr. Machy. This
proves, that a part of rancid fat is put into
a faponaceous ftate by its acid, and by that
means rendered foluble in water, and in fpi-
rit : either of thefe fluids may therefore be
ufed with fuccefs to deprive fat of its ran-
cidity.

When fat is wafhed with a great quantity
of diflilled water, the fluid dififolves a gela-
tinous matter, which may be exhibited by
evaporation j but the fat always retains a cer-
tain portion of this matter, with which it is
intimately combined, and on which its pro-
perty of fermenting depends. The action
of water on this animal fubflance has not
yet been further inquired into.

Meffrs. Crell, and the chemifts of Dijon,
have explained the action of alkaline fub-
ftances on fat. It has been long fmce known,
that the pure alkalis form a kind of foap
with fats. Mr, Crell, by treating foap with

a fo-

FAT. 321

a folution of alum, feparated the oil, and
obtained a folution of the febaceous fait of
vegetable alkali by evaporating the fluid.
He diftilied this fait with oil of vitriol,
which difengaged the febaceous acid. To
deprive this of the portion of vitriolic
acid it may be contaminated with, Mr.
Crell directs it to be re- diftilied from one-
fourth of the febaceous fait of pot-afh, which
muft be referved for this ufe. It may be
afcertained that it contains no more vitriolic
acid by the addition of the acetous fait of
lead : for if the precipitate be totally foluble
in vinegar, it does not contain vitriolic acid.
The chemifts of the academy of Dijon ufe a
more fimple procefs to obtain the febaceous
acid. Suet is melted, and quick-lime added ;
when the mixture is cold, it is boiled in
a large quantity of water, which, by fil-
tration and evaporation, affords the feba-
ceous fait of lime, of a brown colour, and
acrid tafle. This is purified by calcination
in a crucible, folution, and filtration ; a fuf-
ficient quantity of water, impregnated with
cretaceous acid, being added, to feparate the
fuperabundant lime. The fluid being eva-
porated, affords a white fait, from which,
by diftillation with the vitriolic acid, the
febaceous acid is difengaged.

This acid exifts in the butter of cocoa,
fpermaceti, and probably in vegetable oils.
The following are its characters : it is li-

Vol. IV. X quid

322 FAT.

quid, white, and of a very ftrong fmell ; it
emits white fumes, is decompofed by fire,
becomes yellow, and affords cretaceous acid.
It ftrongly reddens blue colours ; unites, in
all proportions, with water -, forms a cryftal-
lizable fait with lime ; and with pot-afh and
foda, falts which cryftallize in needles, and
are fixed in the fire. It appears to ad: on
quartz, and on glafs, like the acid of fyrup.
(See § IV. of the difcourfe placed at the
beginning of the firft volume.) It diffolves
gold, when united with the nitrous acid ;
attacks mercury and filver ; precipitates the
nitre and acetous fait of lead ; it precipi-
tates cream of tartar, and feparates the vine-
gar from tartar, and from the acetous fait
of pot-afh. When ftrongly heated on vitri-
olic falts, it feparates the acid in the ful-
phureous ftate. It precipitates the nitre of
mercury and of filver. Many of thefe pro-
perties induced Mr. Crell to think, that the
febaceous acid might be nothing more than
a modification of the muriatic acid ; but M.
Morveau obferves, that as it decompofes cor-
rofive fublimate, that character alone is fuf-
ficient to diftinguifh them.

Acids produce a change in fat, which is
fimilar to that produced by combuftion.
They likewife appear capable of converting
it into an acid foap, foluble in water.

Sulphur unites very well with fat, and
forms a combination, which has not yet been
accurately examined.

Fat

FAT. 323

Fat is capable of diflblving certain metals ;
it unites with mercury, in the well known
preparation, called mercurial ointment. For
this purpofe, the metal is triturated with
hogs lard for a long time; the mercury
becomes divided, attenuated, and fo inti-
mately united with fat, that it commu-
nicates to it a Hate-colour, and lofes its
metallic form. This union, however, ap-
pears to be nothing more than an extreme
divifion, or at mod there is only a fmall por-
tion of the mercury diflblved by the acid of
the fat, fince globules of mercury may al-
ways be diftinguifhed by a lens in the beft
prepared ointment.

Lead, copper, and iron, of all the metals
are the moil eaiily altered by fat. The calces
of thefe metdls combine very readily with
this fubftance; and for that reafon it is dan-
gerous to ledve food of a fat nature in veffels
of copper, or even in thofe of earth, which
are covered with glafs of lead. In the com-
binations of fat with the calces of metals,
it is obferved, that the latter aflumc readily
the metallic ftate when heated : this phe-
nomenon arifes from the inflammable gas,
which is difengaged from the fat, and unites
with the oxyginous principle of the calx.

Moft vegetable matters are capable of unit-
ing with fat ; extracts and mucilages give it
a degree of folubility in water, or at leaffc
favour its fufpenfion in that fluid.

X z It

324 FAT.

It combines with oils in all proportions,
and communicates to them a part of its con-
fiftence.

Thefe are the chemical properties of fat
which are at prefent known : they teach us,
that this fubftance greatly refembles butter;
that is to fay, it is a kind of fat oil, rendered
concrete by a portion of acid.

With regard to its ufes in the animal eco-
nomy, befides that of maintaining the heat of
thofe parts which it furrounds, and the agree-
able plumpnefs and pliancy it produces, toge-
ther with the whitenefs it communicates to
the fkin : it likewife appears, according to
Macquer, to be of ufe in abforbing the fuper-
abundant acids which may exift in the bodies
of living creatures ; it is, as it were, the
refervoir of thofe falts. It is likewife known,
that too great a quantity of acid, introduced
into the body of an animal, diffolves and
melts the fat, doubtlefs by rendering it fa-
ponaceous, and confequently more foluble.
Theexceffive abundance, and more efpecially
the alterations of the fat, produce dangerous
diforders in the animal economy, whofe
fymptoms and effects have not yet been well
examined. Lorry has particularly attended to
the nature of fat, and has difcovered a ftrik-
ing analogy between this fubftance and bile.
Fat is ufed in foods, and is nourifhing for
fuch perfons as have ftrong digeftive powers.
It is ufed externally in medicine, as a foft-

ening

THE BILE. 325

ening remedy ; and as fuch it enters into the
compofition of ointments and plafters.

The marrow, contained in long bones,
exhibits the fame properties as fat ; but the
comparative analyfis has not been yet made
with fufficient accuracy to defcribe its cha-
racleriftic properties.

CHAP. XIII.

Concerning the Bile and Biliary Calculi.

THE bile, or gall, is a fluid of a green
colour, more or lefs yellow, of an ex-
ceffively bitter tafte, and of a faint and nau-
feous fmell, which is feparated from the
blood by a glandulous vifcus, univerfally
known by the name of the liver. It is col-
lected in moft animals, except infects and
worms, in a receptacle near the liver, called
the gall bladder. The human bile has not
yet been much examined, on account of
the difficulty of procuring a fufficient quan-
tity : the gall of the ox has been more par-
ticularly examined by chemifts.

This liquor is of a glutinous, or almoft
gelatinous confidence -> it pours out like fy-
rup ; and by agitation, it lathers like foap<»
water.

X 3 When

326 THE BILE.

When diftilled in the water- bath, it af-«
fords a phlegm, which is neither acid nor
alkali, but after a certain time putrefies.
This phlegm has often exhibited to me a
lingular character ; it emits an odoriferous
fmell, of confiderable ftrength, and greatly
refembling that of mufk or amber. This
experiment has been made in my courfes of
lectures before a number of fpeclators. It
takes place, more efpecially when bile, (light-
ly altered by having been kept fome days, is
fubmitted to diftillation. When all the wa-?
ter which bile affords in the water- bath has
been diftilled off, the refidue has the form
of an extract, more or lefs dry, and of a deep
and brownifh green. This extract of bile
attracts the humidity of the air, is- very te-
nacious and pitchy, and is totally foluble in
water; by deflrucfive diftillation, it affords
volatile alkali, empyreumatic animal oil,
much concrete volatile alkali, and an elaftic
fluid, confifting of a mixture of cretaceous
and inflammable gas ; after this operation,
a coal remains of confiderable bulk, and lefs
difficult to incinerate than thofe we have
hitherto fpoken of. According to Mr. Ca-
det, who communicated a very valuable me-
moir, on the analyfis of bile, to the Academy,
in the year 1767, this coal contains mineral
fixed alkali, a fait which he thinks to be
of the fame nature as fugar of milk, an ani-
mal ear th; and a fmall portion of iron. It

muft

THE BILE. 327

mufl be obferved, that this diflillation muft
be made flowly, becaufe the matter expands
confiderably. Bile, expofed to a tempera-
ture between 65 and 85 degrees, quickly
changes, its fmell becomes more naufeous,
its colour is deftroyed, whitifh mucilaginous
flakes are precipitated, its vifcidity disap-
pears, and its fmell foon becomes fetid and
penetrating. When the putrefaction is in
an advanced ftate, its fmell becomes fweet,
and refembles amber. My pupil, M. Vau-
guelin, has difcovered, that bile, heated
in the water-bath, and High tly evaporated,
may be afterwards preferved for many months
without alteration, as is likewife the cafe
with refpect to vinegar.

Bile is very foluble in water; and when
thus diluted, becomes of a yellow colour,
which is lighter, in proportion to the quan-
tity of water added.

All the acids decompofe it in the fame
manner as foap, and produce a coagulum.
If this mixture be filtrated, and the fluid
evaporated, a neutral fait is obtained, which
is found to confifl: of the acid made ufe of
and foda. This valuable experiment, firfi
made by Mr. Cadet, proves the exiftence of the
mineral fixed alkali in the bile. The matter
remaining on the filter, in thefe experiments,
is thick, vifcid, very bitter, and very in-
flammable ; its colour and confidence vary,
according to the nature and concentration of
X 4 the

328 THE BILE.

the acid made ufe of. I have obferved, that
the vitriolic acid gives it a deep green co-
lour; the nitrous acid, fomewhat concen-
trated, a brilliant yellow; and the muriatic
acid, a very beautiful light green : thefe co-
lours, however, vary greatly, according to
the ftate of the bile, and of the acids. This
precipitate is a true refin, which fwells,
melts, and takes fire on hot coals, is totally
foluble in fpirit of wine, and precipitable
by the addition of water. The adion of
acids on bile, proves, therefore, that it is a
true foap, formed by an oil of the nature of
refins, combined with foda. They likewife
indicate the prefence of a certain quantity of
the albuminous matter in this animal fluid,
which caufes it to coagulate by fire, by acids,
or by putrefaction.

Neutral falts, mixed with bile, prevent
its putrefaction.

Metallic folutions, and bile, mutually de-
compofe each other; the fixed alkali of this
humour unites to the acid of the folution,
and the refin of the bile precipitates in com-
bination with the metallic calx.

Bile unites readily with oils, and takes
them out of cloaths in the fame manner as
foap.

This fluid is foluble in fpirit of wine,
which feparates the albuminous matter.
The tincture of bile is not decompofed by
water -, which fhews, that this fubftance is

z true

THE BILE, 329

a true animal foap, equally foluble in aque-
ous and fpirituous menftrua. Ether likewife
dilfolves it very readily.

Vinegar decompofes bile in the fame man-
ner as the mineral acids ; when the filtrated
liquor is evaporated, the acetous fait of foda
is obtained, well cryftallized.

From thefe feveral experiments, it fol-
lows, that bile is a compound of much wa-
ter, a peculiar fpiritus rector, albuminous
mucilage, oil of the nature of refins, and
cretaceous fqda. Mr. Cadet found it to con-
tain a fait, which he thinks to be of the
nature of fugar of milk, and whofe exigence
has been fince confirmed by Mr. Van Bo-
chaute.

Bile, confidered with refpecT: to the ani-
mal economy, is a fluid which appears to
affift the procefs of digeftion. Its fapona-
ceous quality renders it capable of uniting
oily fubftances with water. Its bitter tafte
proves, that it ftimulates the interlines, and
promotes their action on the aliments.
Roux, a celebrated phyfician and chemift
of the Faculty of Medicine at Paris, whofe
premature death is a heavy lofs to the
fciences, was of opinion, that the bile is
likewife principally calculated to evacuate
the colouring part of the blood from the
body. It appears to be decompofed in in
.duodenum, by the acids which are almoft
always difengaged in digeftion. It is certain,

at

33<5 THE SILE.

at leaft, that it is greatly altered, efpecially*
in its colour, when it compofes part of the
excrements. Judicious phyficians may there-
fore, in many cafes, make ufeful inferences
from the infpedtion of thefe matters, which
indicate the ftate of the bile, and that of the
liver, which feparates it.

The extract of the gall of bullocks, and of
many other animals, is ufed as a very good fto->
machic medicine. It fupplies the defect and
inactivity of the bile, reftores the tone of
the ftomach, and eftablifhes the functions of
that organ, when debilitated ; but great care
muft be taken in its ufe, becaufe it is acrid
and heating ; and it muft be adminiftered
only in very fmall dofes, efpecially in irri-
table fubjects.

Whenever the human bile is detained ii>
the gall bladder by any caufe, and efpecially
by fpafmodic contractions, as in melan-
cholic or hyfteric diforders, long continued
grief, &c. it thickens, and produces brown,
light, inflammable concretions, of a very
ftrong bitter tafte, which are called biliary
calculi. Thefe concretions are often very
numerous, diftending the gall bladder, and
fometimes intirely filling it. They produce
violent hepatic cholics, vomiting, jaundice,
&c.

Thefe calculi have been examined by M.
Poulletier de la Salle. He has obferved,
that they are difibluble in ardent fpirit.

After

THE BILE. 33I

After having digefted the ftones in fpirit of
wine for a certain time, he obferved, that
the fluid was filled with (lender, brilliant,
and crystalline particles, having all the ap-
pearances of a fait; and the experiments made
on this faline fubftance, (hewed, that it re-
fembles, in certain properties, the acid fait,
known by the name of flowers of benzoin.
From the experiments of this philofopher,
it feems, that this fait is only contained
in the biliary calculi of man, as he did not
find it in thofe of oxen.

The difcovery of M. Poulletier de la Salle,
has been confirmed by facts obferved at the
Royal Society of Medicine, refpecting the
ftones of the gall-bladder. This fociety re-
ceived from feveral phyficians, biliary cal-
culi of a peculiar nature, which have not
hitherto been defcribed. They confift of a
mafs of cryftailine tranfparent laminas, iimi-
lar to mica, or talc, which have abfolutely
the fame form as the fait difcovered by M.
Poulletier, It even appears, that the human
bile is capable of affording a great quantity
of thefe cryftals; for the Society of Medi-
cine is in potfefiion of a gall-bladder intirely
filled with this faline tranfparent concretion.
It is much to be wifhed, that the nature of
thefe new calculi may be examined into, as
refearches on this fubjecl cannot but be very
ufeful to medicine.

From thefe accounts, two kinds of bi-
liary

33^ THE BILE.

liary calculi may be diftinguifhed ; the one,
opake, brittle, inflammable, and truly bi-
lious ; the others tranfparent, cryftallized in
lamina, and appearing to be a faline princi-
ple of the bile, which, though it has not yet
been proved, may perhaps exift in greater
quantities, in certain morbific affections of
this fluid, than in the natural ftate, and
which in this cafe is difpofed to be precipi-
tated and cryftallized, whenever the gall is
detained in confiderable quantities in its
bladder.

Soap, the mixture of oil of turpentine and
ether, &c. have been propofed to diffolve
the biliary calculi. It is an important ob-
fervation, that they are only found in the
gall-bladder of oxen, after dry feafons, and
a fcarcity of frefh fodder ; and that they
difappear in the fpring and fummer, when
thefe animals find abundance of green and
fucculent vegetables. The butchers are well
acquainted with this phenomenon ; they
know that thefe ftones are found in oxen
from the month of November to the month
of March, and not afterwards. This phe-
nomenon fufficiently fhews the power of the
faponaceous juices of plants in diflblving
the biliary calculi.

CHAP.

THE SALIVA. 333

C H A P. XIV.

Concerning the Saliva, the Pancreatic Juice,
and the Gaftric Juice.

ANATOMISTS and phyfiologifts have
obferved a great analogy between the
faliva and the pancreatic juice. The fali-
vary glands, and the pancreas, have in fadt
a ftru&ure intirely of the fame kind, and
the ufe of the fluids, fecreted by thefe or-
gans, appears to be the fame. Man, and
quadrupeds, are the only animals in which
the faliva exifts ; or at leaft the falivary
glands have not been obferved in any other
animals.

No accurate chemical experiments have
yet been made with thefe two fluids. This
circumftance may be attributed to the diffi-
culty of procuring either, even in very fmall
quantities. It is only known, that the fa-
liva is a very fluid juice, feparated by the
parotides, and many other glands, which
continually flows into the mouth, but
molt abundantly during maftication. It
appears to be of a faponaceous nature, im-
pregnated with air, which renders it frothy;
it leaves but a fmall refidue, when eva-
porated

334 THE GASTRIC JUICE.

porated to drynefs -y but it forms, neverthe-
lefs, certain falivary concretions in the paf-
fages which convey it into the mouth. It
appears to contain an ammoniacal fait, iince
lime and cauftic fixed alkalis difengage from
it a penetrating and urinous odour. Pringle,
from experiment, concluded, that the faliva
is very ieptic, and that it favours digeftion,
by exciting a commencement of putridity
in the aliments. M. Spallanzani, and many
other modern phyficians, think, on the con-
trary, that it porTeiles the property of re-
tarding and impeding putrefaction.

The gaftric juice is feparated by fmall
glands, or the arterial extremities, which
open into the internal tunic of the ftomach.
The oefophagus likewife affords a fmall quan-
tity, efpecially in the inferior region. Glands
of confiderable magnitude are obferved in
many birds, which open into very fenfible
excretory dufts.

Modern philofophers have paid great at-
tention to the gaftric juice. Meffrs. Spal-
lanzani, Scopoli, Monch, Brugnatelli, Car-
minati, have, within the laft few years, ex-
amined the properties of this liquor. They
collected it in the ftomach of fheep and
calves, by opening them, after having fuf-
fered them to fail for fome time. They ob-
tained it from carnivorous and gallinaceous
birds, by caufing them to fwallow fpheres
and tubes of metal, pierced with holes, and

filled

THE GASTRIC JUICE. 335

filled witk very fine fpunge. M. Spallan-
zani examined the gaftric juice of his own
ftomach, by procuring a vomit, or by fwal-
lowing wooden tubes, filled with different
fubftances, to judge of the effedfc of the gaf-
tric juice on each of them. The experi-
ments with tubes had been before attempted
by M. De Reaumur. Laftly, M. Goffe of
Geneva had the courage to caufe himfelf to
vomit a great number of times, by a procefs
which is peculiar to himfelf, and confifts in
fwallowing the air. From all the modern
obfervations, the gaftric juice appears to
poffefs the following properties.

It is the principal agent of digeftion, and
changes the aliments into a kind of uniform
foft pafte : it afts on the ftomach itfelf after
the death of animals. Its effecls mew, that
it is a folvent, but of that peculiar nature,
that it diflblves animal and vegetable fub-
ftances uniformly, and without exhibiting a
ftronger affinity for the one than for the
other. Far from being of the*nature of a fer-
ment, it is one of the moft powerful antifep-
tics we are acquainted with : and from the
experiments of the philofophers before cited,
its nature appears to be efTentially different
in the feveral claries of animals. According
to M. Brugnatelli, the gaftric juice of birds
of prey, and granivorous birds, is verv bitter,
and compofed of a difengaged acid, refin,
animal matter, and common fait; that of

ruminating

336 THE GASTRIC JUICE.

ruminating quadrupeds is very aqueous, tur-
bid, and fait, containing volatile alkali, an
animal extract, and common fait. M. de
Moryeau, having digefted portions of the
internal tunic of the ftomach in water, found
that it has an acid character. M, Spallan-
2ani thinks, that this chara&er depends on
the aliments, as he never found the acid
juice in the ftomach of carnivorous animals,
but always in thofe which feed on grain.
M. GofTe made the fame obfervation on
himfelf, after having ufed crude vegetables
for a long time. It therefore appears, ac-
cording to the opinion of M. Spallanzani,
that the gaftric juice, in its natural ftate, is
neither acid nor alkaline, or that, if it con-
tains a peculiar acid, it is in the neutral ftate.
M. Brugnatelli thinks, that the white matter,
in the excrements of carnivorous birds, con-
tains phofphoric acid ; but M. de Morveau
obferves, that his experiments are not con-
clulive. M. Scopoli found fal-ammoniac,
and fufpects that the muriatic acid is pro-
duced by the vital power of animals ; but no
decifive fad: has been brought in fupport of
this opinion ; every circumftance, on the
contrary, tending to (hew, that this acid
comes from the food.

Hence it may be concluded, 1 . That the
gaftric juice is not yet well known ; 2. That
it appears to be different in the feveral claffes
of animals, and in the fame animal, accord-
ing

THE GASTRIC JUICE* 337

ing to the diverfity of food ; 3. That no
proof has been brought to fhew that it is a
peculiar acid ; 4. That its moil remarkable
property coniifts in its great folvent power,
which extends even to bony and metallic
fubftances ; an indifference, or want of pre-
ference between the matter it ads on, and
efpecially a very ftrong analeptic quality,
which it communicates to all the bodies it
is mixed with, and which even puts a ftop
to putrefaction, in fubftances which have
already began to be changed by that pro-
cefs.

This laft property has excited a greater
degree of attention than the others. MelTrs.
Carmanati, Jurine, and Toggia, have ap-
plied the gaftric juice on wounds. M Car-
manati has even ufed it internally; and they
all agree, with refpecl to its antifeptic vir-
tue. Time and experience muft decide on
the efficacy of this new remedy.

Vol. IV. Y CHAP,

338 ANIMAL HUMOURS.

CHAP. XV.

Concerning the Humours, or Animal Mat-
ters, which have not yet been examined ;
fuch as Sweat, the Nafal Mucus, the Ce-
rumen, Tears, the Gum of the Eyes,
the Seminal Fluid, and the Excrements.

'TpHERE are many animal fluids and
■*• matters, which have not yet been ex-
amined. It is therefore not fo much with
a view to exhibit their properties, as to en-
gage young phyficians to make refearches,
equally new and ufeful, that we propofe to
fpeak curforily refpefting the humour of
tranfpiration, of fweat, of the mucus of the
noftrils, the cerumen of the ears, the tears,
the gummy matter of the eyes, the feminal
fluid, and the excrements.

Phyficians have difcovered a great analogy
between the fluid emitted by cutaneous tranf-
piration and urine -, they have obferved, that
thefe excretions mutually anfwer the fame
purpofe in many circumftances, and are
therefore naturally led to confider the vapo-
rous fluid of tranfpiration, as of the fame
nature as urine. Medical practice has fhewn,

that

ANIMAL HUMOURS. 339

that its qualities are fubjeft to variation ; that
its fmell is faint, aromatic, alkaline, or four;
that its confiftence is fometimes glutinous,
thick, tenacious, and that it leaves a refidue
on the fkin ; that it often tinges linen with
various fhades of yellow. M. Berthollet af-
firms, that fweat reddens blue paper, and
that this phenomenon takes place more par-
ticularly in parts affected with the gout. He
thinks it contains the phofphoric acid. It
has been hitherto impoffible to collect a fuf-
ficiently large quantity of this excremental
humour, to examine its properties with ac-
curacy. Many inquiries, therefore, remain to
be made, which can only be undertaken and
purfued by phyficians in peculiar circum-
ftances and occafions.

The humour, prepared by the membrane
of Schneider, which is thrown out of the
noftrils by fneezing, deferves to be care-
fully attended to by phyficians. It is a kind
of thick mucilage, white, or coloured, more
or lefs fluid or confiftent in certain affec-
tions, and more efpecially in catarrhs. No
one has yet examined it.

The yellow, greenifh, or brown matter,
which is collected, and becomes thick, in
the auditory canal, and is known by the
name of wax, becaufe of its confiftence, has
not been examined. It. is very bitter, and
appears to be of a refinous nature; it fome-
times becomes fo concrete, as to ftop the
Y 2 auditory

34.0 TEARS.

auditory canal, and prevent the free paflage
of found : there feems to be fome analogy
between this and the inflammable matter of
the bile.

No one has yet made experiments to dis-
cover the nature of tears, which are pre-
pared in a peculiar gland, fituated towards
the external angle of the orbit, and deftined
by nature to maintain the humidity and
fupplenefs of the external parts of the eye.
This fluid is clear, limpid, and manifestly
fait ; it fometimes iflues out of the eye in
large quantities. In the natural ftate, it
gradually flows into the noftrils, and appears
to dilute the mucus. Moll authors who
have fpoken of this liquor, and in particular
Pierre Petit, a phyfician of Paris, who
published a treatife on Tears about the end
of the laft century, confider them as water
nearly pure. The gum, or humour, which
adheres to the borders of the eye-lids, and
appears to be feparated by the glands of
Meibomius, is not better known than the
tears.

Neither has the chemical nature of the fe-
minal humour been more inquired into than
that of the foregoing matters. The few obfer-
vations, which it has been hitherto poflible
to make on this humour, have fhewn, that
it refembles animal mucilages, becomes fluid
by cold and by heat, and that the action of
fire reduces it to a dry and friable fubftance.

The

SEMINAL MATTER

341

The anatomical and microfcopical obfer-
vations on this fubjecft have been carried
much further. They have fhewn, that the
feminal humour is an ocean, in which cer-
tain fmall round bodies fwim, which poffefs
a rapid motion, and are by fome coniidered
as living animals, deftined to reproduce the
fpecies, and by others as organic moleculas,
adapted to form a living being by their
union. The microfcope, in the hands of a
modern obferver, has likewife fhewn cryftals
formed in the feminal liquor by evaporation
and cooling. It muft be admitted, how-
ever, that thefe fine experiments have not
hitherto been attended with confequences
which have advanced the fciences, but that
they have merely afforded data for the con-
ftruftion of certain ingenious hypothefes.

The food, by which animals are fup-
ported, contain a large quantity of matter,
which is not capable of nourifhing them,
and is rejected out of the inteftines in a folid
form. The excrements are coloured by a
portion of bile, which they carry with them.
The fetid odour they exhale, arifes from the
commencement of putrefaction in their paf-
fage through the inteftines. Romberg is
the only chemift who has examined thefe
matters. He obferved, that the phlegm
afforded by excrements diftilled on the
water- bath, was of a naufeous fmell ; by
warning and evaporation, he obtained a faltr

Y 3 which

34^ URINE.

which melted like nitre, and took fire in
clofe veflels. The diftillation of this matter
in a retort, afforded the fame products as
other animal fubftances. Putrefied excre-
ments afforded an oil without colour or
fmell, which did not convert mercury into
filver, as he had been led to expedt.

It muft be obferved, that the fecal matter
examined by Homberg, was that of men,
fed with coarfe bread, and champaign wine ;
a circumflance which was faid to be ef-
fential, in order to fucceed in the alchemical
experiments he was directed to make. There
can be no doubt, but that the properties of
the excrements muft depend on the nature
of the food, of which they are merely the
refidue.

CHAP. XVI,

Concerning Urine.

TTRINE is a tranfparent excrementitious
S* fluid, of a citron yellow, a peculiar
fmell, and a faline tafte, feparated from thq
blood by two glandular organs, called kid-
neys, and from thence conveyed into a re-
fervoir, which is univerfally known by the
flame of the bladder, and in which it re-r

mains

urine. 343

mains for a certain time. This fluid is a
kind of lixivium, containing the acrid mat-
ters of the animal humours, which, if re-
tained too long in the body, might be pro-
ductive of mifchief and inconvenience. It
is a folution of a great number of falts, and
two peculiar extractive fubftances ; and its
quantity and quality varies according to cir-
cumftances. The urine of man, which we
propofe to examine in particular, differs
from that of quadrupeds ; and the differences
are ftill more considerable between the other
claffes of animals. The ftate of the ftomach,
and that of the fluids in particular, produce
a great number of alterations, which cannot
be afcertained but by a long continued feries
of experiments, few of which have yet been
made. We fhall therefore only fpeak, in this
place, of the urine of the human fpecies in
a healthy ftate.

This fluid is diftinguifhed by phyficians
into two kinds ; the one, called crude urine,
when emitted a fhort time after meals, is clear,
and almoft deftitute of tafte and fmell ; it
contains a much fmaller proportion of the
principles than the other, which is called
urine of the blood, or urine of concoftion.

This laft is not emitted till the procefs of
digeftion is finished, and it is feparated from
the blood by the kidneys ; while the former
appears to be filtrated, in part, from the
ftomach and inteftines immediately to the
Y 4 bladder,

344 URINE.

bladder, by means of the cellular mem-
brane.

The ftate of health, and efpecially the dif-
pofition of the nerves, have Angular effects
on the urine. After hyfteric or hypocon-
driac attacks, it flows in large quantities,
and is without fmell, tafte, or colour. The
diforders of the bones, and of the articula-
tions, have likewife a great influence on this
animal lixivium. It often depofits a great
quantity of matter, apparently earthy, but
which feems to be a calcareous phofphoric fait,
as we {hall hereafter obferve. The urine of
thofe who have the gout is of this kind.
Phyficians, particularly Heriffant and Mo-
rand, have obferved, that when the bones
are affected, or become foft, the urine de-
pofits a large quantity of this matter. It is
likewife obferved, that in the healthy ftate,
the urine contains a quantity of this matter,
which is the bafis of bones, and was pro-
bably more than was required for the nutri-
tion and reparation of thofe organs.

Many foods are capable of communicating
certain peculiar properties to urine. Tur-
pentine produces a fmell of violets, and
afparagus a very fetid fmell, in this fluid.
Such perfons as have weak ftomachs, void
urine, which retains the fmell of fuch
foods as they have taken. Bread, garlick,
onions, foup, and all vegetables, commu-
nicate their own proper fmell to the urine.

From

urine. 345

From thefe fads, it follows that the
urine exhibits phenomena, from which the
phyfician may derive the greateft practi-
cal advantages. But it muft not be con-
cluded, that a fimple infpedion of the urine
is fufficient to determine the nature of a dis-
order, the fex of the patient, and the reme-
dies which are proper to be applied, as cer-
tain empirics pretend.

The human urine, confidered with refpect
to its chemical properties, is a folution of a
confiderable number of different fubftances.
Some of thefe are falts, fimilar to thofe of
minerals, and, as Macquer thinks, are de-
rived from the foods, without having fuffered
any alteration. Others are found to be analo-
gous to the extractive principle of vegetables ;
and laftly, there are others which appear to
be peculiar to animals, and even to urine,
or which have not at leaft been found in
confiderable quantities in the products of
the other kingdoms, nor even in other ani-
mal fubftances, except urine. After having
fhewn the method of extracting thefe feveral
matters from urine, we fhall proceed to the
hiftory of fuch as are peculiar to this fluid,
and have not yet been defcribed.

Urine was formerly confidered as an al-
kaline liquor, or lixivium; but M. Ber-
thollet has remarked, that it always contains
an excefs of phofphoric acid, and reddens
the tincture of turnfole. This phyfician has

obferved,

346 URINE.

obferved, that the urine of gouty perfons
contains lefs acid fait than that of perfons
in perfect health ; that during the fit of the
gout, this fluid is much more acid than
ufual, though not more fo than the urine
of a robuft perfon. He conjectures, that in
gouty patients the phofphoric acid is not
evacuated by urine, as in healthy perfons ;
that it wanders, as it were, and is carried
into the articulations, where it excites irri-
tation and pain. This excefs cf acid in the
urine holds the calcareous phofphat in fo-
lution.

M. Scheele feems to think, that this difen-
gaged acid of urine is not merely phofphoric
acid, but confifts of partly the fame acid as he
has difcovered in the human calculus, and is
called the lithiafic acid by M. de Morveau.
The latter acid, which is capable of concretion
and cryftallization, forms, according to the
Swedifh chemift, the red cryftals which are
depofited from urine, and alio the brick-co-
loured precipitate, obferved in the urine of
fuch as have fevers. The tophaceous concre-
tions, in the articulations of gouty perfons, are
likewife of the fame nature as the calculus ;
that is to fay, for the moft part formed of
the lithiafic acid : hence we fee, that M.
Scheele does not agree in opinion with M,
Berthollet. I mall give my thoughts on the
fubjecT: in the hiftory of the calculus of the
bladder.

Frefh

urine. 347

Frefh urine, diftilled in the water-bath,
affords a large quantity of phlegm, which is
neither acid nor alkaline, but quickly pu-
trefies. As this phlegm contains nothing
of value, the urine is commonly evapo-
rated on a naked fire. In proportion as the
water, which forms more than feven-eighths
of this animal humour, is diffipated, the
urine becomes of a brown colour ; a pulve-
rulent matter is feparated, of an earthy ap-
pearance, which has been taken for felenite,
but is a true fait of difficult folubility,
and is compofed of the phofphoric acid and
lime, with a fmall excels of acid. This
fait is of the fame nature as the bafis of
bones, and is mixed with a fmall quantity
of concrete lithiafic acid. When the urine
has obtained the confiftence of a clear fyrup,
it is filtrated, and fet in a cool place; at the
end of a certain time, faline cryftals are de-
pofited, which confift of marine fait, and
two peculiar faline fubftances. Thefe falts
are known by the names of fufible fait, or
native fait of urine : we mall examine their
properties in the following chapter. Seve-
ral fucceffive produ&s of thefe cryftals are
obtained, by repeated evaporations, at the
fame time that a certain quantity of marine
and febrifuge fait cryftallizes. When the
urine affords no more faline matter, it is in
the ftate of a very thick brown fluid, which
is a kind of mother water, and holds in

folution

348 URINE.

folution two peculiar extra&ive fubftances.
By evaporating it to the confidence of afoft
extract, and treating the refidue with fpirit
of wine, Rouelle the younger has difcover-
ed, that a portion is diflblved, and the other
part remains untouched. He calls the firft
faponaceous matter, and the fecond extractive
matter.

The faponaceous fubftance is faline, and
capable of cryftallization. It is not dried
without difficulty; and in this ftate it at-
tracts the moifture of the air. By deftruCtive
diftillation, it affords half its weight of am-
moniacal chalk, a fmall quantity of oil, and
ammoniacal muriate. Its refidue converts
the fyrup of violets to a green.

The extractive fubftance, foluble in water,
and not in fpirit of wine, is eafily dried in
the water-bath, like the extra&s of plants ;
it is black, lefs deliquefcent than the for-
mer, and affords, by diftillation, all the pro-
ducts of animal matters. Such, according
to Rouelle, are the charaCteriftic properties
which diftinguifh thefe two component parts
of the extract of urine. We may likewife
add, that this celebrated chemift obtained
from one ounce to an ounce and a half of
extract from a pint of urine, voided after con-
coition -, whereas the fame quantity of crude
urine afforded no more than one, two, or
three drachms.

If the extracft of urine, inftead of being

fepa-

URINE,

349

feparated by fpirit of wine, be diftilled intire,
it affords much ammoniacal chalk, a very
fetid animal oil, ammoniacal muriate, and a
fmall quantity of phofphorus : its coal con-
tains a fmall proportion of muriate of foda,
or common fait. ' This analyfis of urine
(hews, therefore, that it is compofed of a
large quantity of water, the difengaged phof-
phoric and lithiafic acids, muriate of foda,
combinations of the phofphoric acid with
calcareous earth, mineral alkali, and volatile
alkali, together with two peculiar extractive
matters, which give the fluid its colour. As
to the deep colour it acquires in many dif-
orders, and efpecially in all bilious affec-
tions, I have difcovered, that it is produced
by the reiin of the bile, and that its ex-
trad:, diffolved by fpirit of wine, is preci-
pitated by water.

Urine when expofed to the air, changes more
quickly in proportion as the atmofphere is
hotter, Deporitions are firft formed by fim-
ple cooling; feveral faline matters cryftal-
lize at its furface and bottom, and frequent-
ly a reddifli fait, which appears to be of the
nature of the calculus. No one has ob-
ferved the fpontaneous changes of this ex-
crementitious fluid but Mr. Halle, my af-
fociate. He has diftinguifhed, in the de-
compofition of urine left to itfelf, feveral
terms, or periods, which afford fediment,
or cryftals, of different natures, and are at-
tended

350 tJRIN^E.

tended with various changes. Our prefent
purpofe not extending to the detail of all thefe
changes, which are accurately defcribed in
an excellent Memoir, inferred among thofe
of the Royal Society of Medicine for the
year 1779, we mall confine ourfelves to the
principal alterations to which it is fubje£t.
Soon after it has become cold, its fmell
changes, becomes ftronger, and indicates
the prefence of volatile alkali ; its colouring
matter changes, and is feparated from the
reft of the liquor ; laftly, this alkaline fmell
is diffipated, and is followed by another, lefs
penetrating, but more difagreeable and nau-
feous ; and the decompofition proceeds to
its complete termination. Rouelle the
younger has obferved, that crude and ferous
urine does not putrefy fo quickly ; that its
fmell, after it has become changed, differs
greatly from that of the urine of concodtion ;
and laftly, that it becomes covered with
mouldinefs, like the juices of vegetables, and
folutions of animal jelly. Mr. Halle has
obferved certain urines which became very
acid before they paffed to the ftate of putre-
faction. Urine, putrefied for a year, or
more, affords fufible fait, as well as frefh
urine -y but it affords a much larger quantity
of difengaged phofphoric acid, and effer-
vefces with cretaceous volatile alkali. The
putrefaction extricates and drivems off a part
of the volatile alkali. The fait depo-
sited

URINE. 35I

fited on the fides of the veflel during evapo-
ration, is ftrongly acid ; and the quantity
may be increafed, by adding volatile alkali,
according to the advice of Rouelle the
younger.

Quick-lime, and dry fixed alkalis, imme-
diately decompofe the principles contained
in urine. Nothing more is required, than
to pour a folution of cauftic, vegetable, or
mineral alkali, into frefh urine, in order to
produce an infupportable putrid alkaline
fmell. This is produced by the decompo-
fition of the ammoniacal phofphat. M.
Berthollet has difcovered, that lime-water,
added to frefh urine, produces a precipitate,
from which phofphorus may be obtained.
This phenomenon depends on the union of
the lime with the excefs of phofphoric acid ;
and the precipitate confifts of, 1. The cal-
careous phofphat, naturally contained ia
urine, and which was fufpended merely by
the excefs of phofphoric acid; 2. An ad-
ditional portion of calcareous phofphat,
formed by the union of the fuperadded lime
with the difengaged acid. M. Berthollet,
having obferved that cauftic volatile alkali
likewife precipitates the calcareous phof-
phat of urine, by neutralizing the difen-
gaged phofphoric acid which held that fait in
folution, remarks, that the weight of this
precipitate, compared with that produced
by lime-water, indicates the quantity of dif-
engaged

352 URINE.

engaged phofphoric acid contained in the
urine ; becaufe, in faft, the ammoniacal
phofphat, formed in this experiment, re-
mains diffolved ; whereas the calcareous
phofphat produced by lime-water, being
infoluble, is precipitated at the fame time
as the other portion of calcareous phofphat,
which naturally exifts in the urine.

Acids have no adtion on frefli urine, but
they quickly take away the fmell of putre-
fied urine, and of the depofitions it forms in
that ftate.

Urine decompofes many metallic folu-
tions. Lemery diftinguifhed by the name
of the rofe-coloured precipitate, a magma
of that colour, which ' is formed when
the nitrous folution of mercury is poured
into urine. This precipitate is partly form-
ed by the muriatic acid, and partly by
the phofphoric acid contained in this fluid.
M. Brongniart has obferved, that this pre-
paration fometimes takes fire by friction,
and burns rapidly on hot coals ; he attri-
butes this effect to a fmall portion of phof-
phorus.

Such is the Drefent ftate of our know-
ledge refpe&ing the chemical properties of
urine. Much remains to be done, before
we may efteem ourfelves in pofleffion of all
that analyfis is capable of difcovering with
regard to this fluid. It is neceffary, for this
purpofe, to examine the different depofitions

obferved

PHOSPHORIC SALTS. 353

abferved in urine, and well defcribed by
Mr. Halle, the red or tranfparent faline
:oncretions which are formed, and which
Mr. Scheele takes to be the lithiafic acid ;
the abundant fediment which urine affords
ifter fits of the gout, in fuch as are attacked
by the ftone, &c.

We (hall now proceed to examine the pe-
culiar faline products, obtained from urine,
to whofe properties it is very neceffary to
attend.

CHAP. XVII.

Concerning the Ammoniacal Phofphat, the
Phofphat of Soda, and the Calculus in
: the Bladder.

"1 X/E have feen that urine contains many
*^ peculiar falts ; thefe falts are combi-
nations of the phofphoric acid with volatile
alkali, ioda, and lime, and the bafe of the
calculus of the bladder. We fhall fucceffive-
lv examine thefe fubftances under the de-
nominations given them by M. de Morveau,
of ammoniacal phofphat, phofphat of foda,
and lithiafic acid. We fhall defcribe the
properties of the calcareous phofphat when
we treat of bones.

The fait, obtained by the cooling of eva-
Vol. IV. Z porated

354 PHOSPHORIC SALTS.

porated urine, has been called fufible fait id
general, becaufe it melts in the fire, as wc
ihall prefently fee ; it has likewife been call-
ed erTential fait of urine, or microcofmic fait:
in this firft flate, it is far from being pure,
but is contaminated by an extractive fub-
ftance, together with marine fait and phofphat
of foda. Several chemifls, Margraaf in par-
ticular, fuppofed that it was neceflary, in
order to avoid the mixture of marine fait,
that the urine fhould putrefy; they ima-
gined, that the marine fait became converted
into fufible fait by the putrid action ; a fadt
which is now known to be falfe. One hun-
dred and twenty pounds of recent urine, af-
ford, according to Margraaf, about four
ounces of this fait, and two ounces of phof-
phat of foda.

The accurate feparation of thefe two falinc
fubftances, which Shockwitz, le Mort, Bo-
erhaave, Henkel, and Schloffer, confidered as
one and the fame filt, is not eafy. To effect
this, the ufual advice is to diifolve the fufible
fait in hot water, evaporate the fluid, and
cryftallize it. But Rouelle the younger, and
the Due de Chaulnes, are the only che-
miits who have mentioned a very great and
lingular difficulty prefented in this procefs.
The greateft part of the fufible fait is difli-
pated by the heat when the folution is evapo-
rated; three-fourths being loft by this means.
The Due de Chaulnes has defcribed a pro-
cefs

PHOSPHORIC SALTS. 355

cefs for purifying it with the leaft poffible
lofs : it confifts in diffolving, filtering, and
cooling this folution in well clofed veffels ;
in either cafe, a fait, cryftallized in very flat,
rhomboidal four-fided prifms, is obtained,
which is the ammoniacal phofphat; and
above thefe firft cryftals, another fait, in
cubes, or rather in long, fquare tablets, very
different from the other, and which is the
phofphat of foda : this laft may be feparated,
according to the remark of Rouelle the
younger, by removing its efflorefcence from
the former, which does not change.

Ammoniacal phofphat, thus purified, and
feparated from the phofphat of foda, has the
form of very flat, rhomboidal tetrahedral
prifms, as we have obferved, which are often
truncated lengthwife on their acute edges,
by which they become converted into a kind
of hexagonal prifms ; there are likewife
found, according to Rome de Lifle, from
whom the prefent defcription of this fait is
taken, longitudinal fegments of thefe prifms,
whofe longed face refting on the veffel, has a
rhomboidal form, and is interfered by two
diagonal lines. The tetrahedral, and octa-
hedral forms, attributed to this fait, are not
met with, excepting when it contains marine
fait and phofphat of foda ; the muriate of
foda appears more particularly to poiTefs the
property of modifying the form into that of
an octahedron, fince marine fait, diffolved
Z z in

356 PHOSPHORIC SALTS.

in urine, and expofed to the fun, affords
regular o£tahedrons at the end of fome days.
The tafte of this fait is at firft cool, after-
wards urinous, bitter, and penetrating ;
when placed- on a burning coal, it fwells,
emits a fmell of volatile alkali, and melts
into a deliquefcent globule, when urged by
the blow-pipe. If diftilled in a retort, very
penetrating and cauftic volatile alkali is dif-
engaged ; the refidue is a tranfparent glafs,
very fixed, and very fufible, which attacks
the glafs of the retorts. Margraaf affirms,
that it is foluble in two or three parts of
diftilled water, and prefents the characters
of an acid. M. Rouelle affirms, that it
is deliquefcent. M. de Morveau, on the
contrary, thinks that by means of heat
it may be brought into the ftate of a per-
manent glafs. M. Prouft has difcovered,
that this vitreous refidue is a combination of
the phofphoric acid with a portion of a pe-
culiar matter, which he did not appear to
be acquainted with ; but which, from the
inquiries of feveral modern chemifts, has
been found to be phofphat of foda. It muft
however be obferved, that this compound
glafs is not obtained, excepting when am-
moniacal phofphat, which ftill retains a por-
tion of the phofphat of foda, is diftilled, and
that in this cafe the glafs appears to be al-
ways either opake, or very capable of be-
coming

PHOSPHORIC SALTS. 357

coming fo, while very pure ammoniacal
phofphat leaves a tranfparent glafs.

The ammoniacal phofphat is not changed
by expofure to air.

It is very foluble in water, no more than
five or fix parts of cold water being required
to hold it in folution. Hot water, at the
temperature of 17c degrees, decompofes it,
and even volatilizes a portion of its acid.

The ammoniacal phofphat caufes filiceous
earth, clay, ponderous earth, magnefia, and
lime, to enter into fufion ; but thefe vitreous
compounds are effected by the phofphoric
acid, the volatile alkali itfelf being driven
off.

Quick-lime, and the two pure fixed al-
kalis, decompofe ammoniacal phofphat, and
feparate the volatile alkali : if lime-water be
poured into a folution of this fait, a white
precipitate is obtained, which confiils of
calcareous phofphat. The alkalis and all the
cretaceous neutral fajts decompofe it like-
wife, and feparate the volatile alkali in the
form of ammoniacal chalk.

The action of the mineral and the vege-
table acids on ammoniacal phofphat has not
yet been fufficiently examined. This action
is referable to the various elective attractions
which exift between the phofphoric acid and
its alkaline bafe : we fhall treat of them
when we come to fpeak of that acid.

Z 3 Wc

358 PHOSPHORIC SALTS*

We fliall likewife refer the alterations
ammoniacal fait is fufceptible of, from me-
tals and their calces, to the fame part of our
work, becaufe thofe alterations abfolutely
depend on the pholphoric acid.

Ammoniacal phofphat, treated with char-
coal in clofe veffels, affords phofphorus.
Bergman has propofed it as a flux in affays
with the blow-pipe.

We have already defcribed the method of
obtaining the phofphat of foda by itfelf * it
will be proper, in this place, to mention
the feveral dates of this difcovery.

Hellot appears to be the firft who fpoke
of it, in the year 1737, but he took it for
felenite. Haupt mentioned it in 1740, un-
der the name offal mirabile perlatum.f Mar-
graaf defcribed it in the year 1745. ^ott
fpoke of it in 1757 ; and, like Hellot, took
it for felenite. Rouelle the younger exa-
mined it particularly in the year 1776, and
called it fufible fait, with bafe of natrum.
All thefe chemifts perceived the difference
between this fait and the foregoing, to con-
fift more efpecially in its not affording phof-
phorus with charcoal ; but Rouelle afcer-
tained its properties better than any other
chemift; according to him, its crystals are
flat, irregular, tetrahedral prifms, one of
whofe extremities is dihedral, and compofed
of two rhomboids, the other end adhered to
the bafe. The four fides of the folid, are

two

PHOSPHORIC SALTS. 359

two alternate irregular pentagons, or two
long rhombufes.

The phofphat of foda, or fufible fait, with
bafe of natrum, expofed to the fire in a cru-
cible, melts, and affords a white opake mafs;
when heated in a retorr, it gives out phlegm,
without any character either of acid or al-
kali ; its refidue is a glafs, or opake frit.

This fait efflorefces, and falls intirely into
powder, by expofure to air.

It readily diflblves in diitilled water, and
cryftallizes by evaporation -, its folution con-
verts the fyrup of violets to a green.

Calcareous nitre decompofes it, and af-
fords a precipitate of calcareous phofphat :
the fupernatant liquor affords a nitre of foda.
This fait is likewife decompofed by the ni-
trous folution of mercury. It affords a white
precipitate, which, diftilled in a retort, pro-
duces a fmall quantity of reddifli fublimate,
with running mercury, and leaves at the bot-
tom of the veiTel a white opake mafs, adhering
to and combined with the glafs. This mer-
curial precipitate, boiled with a folution of
the fait of foda, forms agiin the fufible fait
with bafe of natrum, and leaves the mer-
cury in the ftate of a brick-dull powder. All
thefe fa&s were discovered by Pvouelle the
younger. M. Prouft, at the inftance of this
celebrated chemift, whole pupil he was, made
a confiderable number of experiments, the
principal refults of which are the following,

Z 4 The

360 PHOSPHORIC SALTS.

The refidue of phofphorus, made with fufible
fait of the firft cryftallization, from which
no more than one-eighth of fait of phof-
phorus had been obtained, was lixiviated,
and, by evaporation in the open air, afforded
quadrangular cryftals, of an inch in length,
whole quantity, according to him, amount-
ed to five or fix drachms in the ounce of
fufible fait employed in making the phof-
phorus. We muft obferve, that the quan-
tity mull be diminifhed, on account of the
water which enters into the cryftals. This
faline fubftance melts by fire into an opake
glafs ; colours flame green ; efHorefces in the
air ; decompofes nitrous and marine falts,
by difengaging their acids ; forms glaffes with
earthy matters in a melting heat, and fatu-
rates alkalis like an acid. From this exa-
mination, IV] . Prouft thinks it different from
all the faline fubftances known, that it was
united with the phofphorie acid and volatile
alkali in the ammoniacal phofphat, and that
it formed with foda the fufible fait with bafe
of natrum, of Rouelle. He obferved, that it
adled as an acid, and compared it to fedative
fait 5 and with this idea M. Prouft made
new experiments on the fufible fait of bafe
of natrum, obtained by the procefs of Rou-
elle before defcribed.

According to him, lime decompofes this
fait, and has a ftronger affinity with the
opake fubftance, which ferves the purpofe

of

PHOSPHORIC SALTS. 361

of an acid, than with foda. If lime-water
be poured into a folution of this fait, a pre-
cipitate is afforded, and the mineral alkali
remains pure and cauftic in the folution.

The mineral acids, and even diftilled vine-
gar, decompofe it by a contrary operation.
Rouelle fuppofed that the vitriolic and nitrous
acids did not adt on this {alt, becaufe they
occafion no apparent change; but M. Prouft
having mixed the vitriolic, nitrous, muriatic,
and acetous acids, each feparately, with a folu-
tion of fufible fait, with bafe of natrum, ob-
ferved, that though no precipitate was af-
forded in thefe mixtures, the liquors by eva-
poration and cooling afforded vitriol and
nitre of foda, marine fait, and the acetous
fait of foda, which proves, 1. That this
fait was decompofed by the acids. 2. That
it contains foda, as Rouelle the younger had
fhewn. As to the feparate fubftance which
was before united to the mineral alkali, it is
evident that it remains in folution in the fluids,
at the fame time with the newly formed
neutral falts. M. Prouft has obferved, that
after the mixture of vinegar, and the cryftal-
lization of the acetous fait of foda, if eight or
ten times its weight of hot fpirit of wine be
poured into the mother water, the laft por-
tions of the neutral acetous fait werediffolved,
and a magma was formed, which he wafhed
with new fpirit of wine, and afterwards dif-

folved

362 PHOSPHORIC SALTS.

folved in diftilled water. This folution of
magma evaporated in the open air afforded
cryftals in quadrangular prifms, abfolutely
fimilar to thofe obtained from wafhing the
refidue of phofphorus made with the fufible
fait obtained in the firft cryftallization of
urine. This peculiar fubftance therefore,
which refembles fedative fait, according to
M. Prouft, faturates the foda in the fufible
fait with bafe of natrum. This difcovery
feems, in fact, to explain why it does not
afford phofphorus. To thefe details, M.
Prouft added, that this new fubftance al-
ways exifting in the true fufible fait, or
ammoniacal phofphat, communicated to the
phofphoric acid the property of melting
into glafs ; for which reafon I called it by
the name of bafe of phofphoric glafs, in the
firft edition of this work; but M. de Mor-
veau has fince afcertained, that the pure
phofphoric acid obtained by phofphorus fal-
ling into deliquefcence, and confequently
not containing this fubftance, melts alone by
heat into a foiid and permanent glafs. The
feries of experiments which M. Prouft made
with great care, and which is highly intereft-
ing in its refults, induced Bergman to confi-
der this fubftance as a peculiar acid, and he
accordingly has given an account of it in the
fecond edition of his Differ tation on the Elec-
tive Attractions, by the name of acid of fal
perlatum, acidum perlatum, doubtlefs from

the

PHOSPHORIC SALTS. 363

the denomination given by Haupt in the
year 1740, to the fufible fait with bafe of
natrum. M. de Morveau has fince made it
a particular article in his Dictionary of Che-
miftry, under the name of the ouretic acid,
derived from the greek name of urine which
affords it^ But fince the time of the experi-
ments of M. Prouft, the Differtation of
Bergman, and the writing of the article by
M. de Morveau, M. Klaproth has published
in Crell's Chemical Journal, an analyiis of
the fufible fait, with bale of natrum, which
deftroys the exiftence of this pretended pe-
culiar acid ; and fhews, that it is merely
phofphoric acid combined with foda. M.
Klaproth afcertained this fad: by an experi-
ment fimilar to that of Rouelle the younger;
he precipitated the fufible fait with bafe of
natrum, by calcareous, marine, or nitrous
fait, the precipitate which Rouelle had be-
fore defcribed.as fimilar to the bafe of bones
was found to afford phofphoric acjd, by
means of the vitriolic acid. M. Klaproth
adds, that by faturating the phofphoric acid,
obtained by the flow combuftion of phof-
phorus with foda, even to a fmall excefs, a
fait abfolutely fimilar to the fal perlatum
of Haupt, or to the fufible fait with bafe
of natrum of Rouelle, is obtained ; and that
in order to produce the fubftance defcribed
by M. Prouft,' nothing more is neceffary
than to deprive this fait of the excefs of

foda

364 PHOSPHORIC SALTS,

foda by vinegar, or to add a fmall quan-
tity of phofphoric acid. It is not therefore
to be wondered at, after this difcovery, that
Bergman found abfolutely the fame elective
attractions in the perlate acid, and the phof-
phoric acid. Thefe fads have been ftated
by M. de Morveau in a fupplement to the
mineral acids; and he obferves, that after this
difcovery, no further queftion will be made
concerning either the ouretic acid or its falts.
It is very fingular that the phofphat of foda,
or fal perlatum, which after what has been
faid, may properly be diflinguiflied by the
former name, is not decompofed by char-
coal like the ammoniacal phofphat, though
this combuftible fubffcance deprives the
phofphoric acid of the bafe of vital air, or
the oxyginous principle. The foda deprives
this laft acid of the property of being de-
compofed by charcoal, though it does not
a£l in the fame manner on the vitriolic, or
other acids. This is a ftrong exception to
the ele&ive attractions of the oxyginous
principle, and flands alone ; it is equally
remarkable, that the acid of phofphorus ad-
ded in excefs to the phofphat of foda, leaves
this compound, which conftitutes, accord-
ing to M. Klaproth, the peculiar fubftancc
of M. Prouft, the property of converting
fyrup of violets to a green. M. de Morveau
adds to the hiftory of phofphat of foda, that
when a folution of the muriate of lead is
poured into a folution of this fait, a preci-
pitate

CALCULUS IN THE BLADDER. 365

/itate of phofphat of lead is afforded, which
yhen diflilled with charcoal affords phof-
)horus, as M. Laumont, infpe&or of the
nines has difcovered, with one of the ores
>f Huelgoet. Hence we may perceive, how
he plumbum corneum propofed by Mar-
jraaf in the diftillation of phofphorus of
lrine may augment the quantity of the
)rodu&, as we mall explain in the follow-
ng chapter.

The calculus or flone which is formed in
:he human bladder, has long engaged the
tttention of phyficians and chemifts. Para-
:elfus, who gave it the barbarous name of
iuelech, fuppofed it to be formed by an ani-
nal refin, and compared it to arthritic con-
cretions. Van Helmont confidered it as a
concretion made by the falts of urine, and
in earthy volatile fpirit ; and fuppofed that
it differed from the arthritic fait, which was
:aufed, according to him, by the thickening
and acidification of the nutritive fluid. Boyle
-xtraded from it oil, and much volatile fait.
Boerhaave admits it to contain an earth
united to volatile alkali. Hales obtained
645 times its volume of air, and out of 230
grains, the refidue was only 49 ; he called
it animal tartar. Many learned phyficians,
and efpecially Whytt and Deften, have confi-
dered alkaline matters as the true folvent of
the urinary calculus : many have even propof-
ed foap lees, but their conclufions were not

founded

366 CALCULUS IN THE BLADDER.

founded on an accurate analyfis of the cal-
culus. Meffrs. Scheele and Bergman began
this analyfis ; they firft difcovered, that the
ftone in the bladder is formed for the moft
part of a peculiar acid, which M. de Mor-
veau calls the lithiafic acid: 70 grains of cal-
culus affords by diftillation 28 grains of this
acid dry and fublimed, fome volatile alkali,
and 12 grains of charcoal, very difficult to
incinerate -> 1000 grains of boiling water
difTolved 296 grains of the fame acid. This
folution reddened blue colours, but the
greater part of the acid feparated by cooling
in the form of fmall cryftals.

The concentrated vitriolic acid diflblves
the calculus by the affiftance of heat, and be-
comes converted into fulphureous acid. The
muriatic acid does not attack it, the nitrous
acid diffolves it completely, nitrous gas and
cretaceous acid being difengaged during its
adion ; this folution is red, and contains an
acid at liberty ; it dyes the (kin, and other
animal coverings of a red ; no appearance
of vitriolic acid is obferved by the teft of
foluble ponderous falts, nor of lime by the
faccharine acid. Lime-water forms a pre-
cipitate, foluble in acids without effervef-
cence ; cauflic alkalis diiTolve the calculus,
according to M. Scheele. Thefe folutions
are precipitated by lime; 1000 grains of
lime-water diiTolve 537, and the volatile al-
kali in great quantity likewife attacks the
calculus. The fame cheouii affirms, that

the

CALCULUS IN THE BLADDER. 367

the brick-duft coloured depofition of the
urine of fuch as labour under fevers, is of
the fame nature. Though M. Scheele did
not find lime in the flone of the bladder,
Bergman obtained it by precipitating its ni-
trous folution by the vitriolic acid, and by
calcining the relidue of the fame nitrous folu-
tion. Bergman has befides difcovered in the
calculus, a white fpongy matter, infoluble
in water, acids, and alkalis ; the incinerated
charcoal of this fubftance, whofe quantity
was too fmall to permit him to afcertain its
nature, is not even foluble in the nitrous
acid.

From the analyfis of thefe two celebrated
chemifts, which has been often repeated
with the fame refults in the laboratory at
Dijon, the calculus appears to be of the
fame nature as the earth of bones ; yet Mr.
Tennant, of the Royal Society of London,
obferved flones of the bladder which only
loft two-thirds by calcination, and whofe
refidue melted into a glafs, which became
opake by cooling, and confequently con-
tained a very coniiderable quantity of calca-
reous phofphat.

As to the lithiafic acid, its properties, as
far as they are at prefent known, 1. A con-
crete and cryftalline form : 2. Difficult folu-
bility in water ; and in much larger quan-
tity in hot than in cold water : 3. It changes
the nature of the nitrous acid, part of whofe

oxyginous

368 CALCULUS IN THE BLADDER.

oxyginous principle it abforbs, and then
forms a reddifh deliquefcent mafs, colouring
many bodies : 4. It unites with earths and
metallic calces, forming peculiar falts, which
M. de Morveau calls lithiafites of lime, of
pot-afh, of foda, of copper, &c. : 5. It
prefers alkalis to earths: 6. It yields thefe'
bafes to the moft feeble acids, even to that
of chalk, which is the*caufe of the infolu-
bility of the calculus in cretaceous alkalis.
This laft character is peculiar to the prefent
acid ; however there remains, as M. de
Morveau well obferves, much to be done,
reflecting the lithiafic acid ; to which I
may add, that it remains to be afcertained
whether it be not the modification of fome
other acid, as may be fufpected from the
known refemblance between the faccharine
and oxaline acids, as well as between the
pretended perlate or ouretic, and the phof-
phoric acid.

M. de Morveau thinks, that the arthritic
concretions, which phyficians have fuppofed
to be of the fame nature as the calculus of
the bladder, are very different from that
fubftance ; but he grounds his opinion only
on certain experiments of Schenckius, Pi-
nelli, and Whytt, which are far from
poffeffing the accuracy at prefent required
in experimental philofophy 5 and the obfer-
vations of Boerhaave, Frederick Hoffman,
Springsfield, Alfton, Leger, &c. on the good

effect

PHOSPHORUS. 369

effects of alkaline waters, foap, and lime-
waters, on the arthritic and calculous af-
fections, appear to me more proper to afcer-
tain the exiftence of an analogy between thefe
tvyo kinds of concretions, than the former
are capable of difproving it. It muft however,
be ailowed, as M. de Morveau obferves,
that experiment alone is fufficient to decide
the queftion, which .affords an additional
proof of the great importance of chemical
refearches in the art of medicine, and the
advantages it promifes to that ufeful fcience.

CHAP. XVIII.

Of the Phofphorus of Kunckel.

pHOSPHORUS is one of the mod
•** combuftible fubitances we are acquaint-
ed with. As it was originally obtained from
urine, and the fubftance which affords it in
the greateft quantity, is the ammoniacal
phofphat, whofe properties we have juft ex-
amined, we think it proper to treat of the
hiflory of this fubftance in this place.

According to Leibnitz, the difcovery of
phofphorus is due to an alchemift named
Brandt, a citizen of Hamburg, who dis-
covered it in 1667. Kunckel affociated with

Vol, IV. A a a cer-

370 PHOSPHORUS,

a certain perfon named KrafFt, to purchafc
this fecret ; but the latter having purchafed
it, and refufmg to communicate it to Kunc-
kel, he refolved to make a feries of experi-
ments on urine, from which he "knew it was
extracted, in order to difcover it. His in-
quiries were attended with fuccefs, and
therefore he ought to be regarded as the
true inventor. Some perfons likewife attri-
bute the honour of this difcovery to Boyle,
who in fad: depofited a fmall quantity, in
the year j68o, in the hands of the fecretary
of the Royal Society of London ; but Stahl
affirms that KrafFt told him that he com-
municated the procefs of making phofphorus
to Boyle : Boyle communicated his procefs
to a German, named Godfreid Hanckwitz,
who had a good laboratory at London, and
was for a long time the only perfon who made
phofphorus, and fold it to all the philofophers.
throughout Europe. Notwithstanding a great
number of receipts for making phofphorus, and
among others thofe of Boyle, KrafFt, Brandt,
HofFman, Teichmeyer, Frederic HofFman,
Neiwentyt, and Wadelius, have been pub-
lished, fince the year 1680, to the com-
mencement of the prefent century, no che-
mift fucceeded in preparing it ; and the pro-
cefs was in reality a fecret, till a ftranger,
in the year 17^7, ofFered at Paris to com-
municate a fuccefsful method of making
phofphorus. The Academy nominated four

chemifts,

PHOSPHORUS. 37I

chemifts, Hellot, Dufay, Geoffroy, and Du-
hamel, to attend this operation in the labora-
tory of the Royal Garden. The procefs fuc-
ceeded very well, the minifter rewarded the fo-
reigner, and M . Hellot defcribed it very accu-
rately, in a memoir inferted among thole of the
Academy for the year 5737. The operation
confifts in evaporating five or fix hogfheads of
urine, till it is reduced into a granulated,
hard, black, and mining fubftance ; this re-
fidue is calcined in an iron pot, whofe bot-
tom is heated red-hot, till no more fumes
arife, and a fmell like that of peach bloflbms
is perceived -, the calcined matter is lixivi-
ated with about twice its weight of hot wa-
ter, and is dried after the water has been
decanted off. Three pounds of this matter
are then mixed with one pound and a half
of coarfe fand, or pounded ftone-ware, and
four or five ounces of the powder of char-
coal of beech. This mixture being moif-
tened with half a pint of water, is intro-
duced into a Heffian retort; the matter is
affayed, by making a portion red-hot in a
crucible : if it emit a violet flame, with a
fmell of garlick, it is a proof that phofpho-
rus will be afforded. The retort is placed
in a furnace built on purpofe, and a large
receiver is adapted, two-thirds full of wa-
ter ; the receiver muft have a fmall hole
pierced in it ; and M. Hellot confiders this
as one of the moil neceifary circumftances
A a 2 te

372 PHOSPHORUS.

to infure fuccefs. Three or four days after
the apparatus has been put together, a fire
is made, fo as very gradually to dry the
furnace and the lutes. The fire is raifed
by degrees to the moil extreme heat, and
kept up in that ftate for about twenty
hours ; the phofphorus does not come over
till about fourteen hours after the com-
mencement of the operation, which in the
whole lafts twenty-four hours. A large
quantity of concrete volatile fait firft rifes,
which is partly diffolved in the water of the
receiver : the volatile, or aeriform phofpho-
rus, firft paffes in luminous vapours ; the
true phofphorus next comes over, in the
form of an oil, or refembling melted wax.
When no more paries over, the apparatus is
left to cool for two days ; the receiver is
then unluted, and water is added to loofen the
phofphorus adhering to the fides ; the phof-
phorus is then melted in boiling water, and
cut into fmall pieces, which are introduced
into the necks of matraffes, cut towards the
middle of the body into the form of a fun-
nel, and plunged in boiling water; the
phofphorus melts, is purified, and becomes
transparent, by the feparation of a blackifh
matter, which riles to the top ; it is after-
wards plunged in cold water, by which it
is congealed, and is thruft out of the necks
of the matraffes by a fmall flick introduced
at the leffer end. Such, infhort/is thepro-

cefs

phosphorus. 373

ccfs defcribed by Hellot. The length of the
operation deterred chemifts from repeating
it, excepting Rouelle the elder, who per-
formed it feveral times with fuccefs in his
chemical lectures.

In the year 1743, Margraaf published, in
the Memoirs of the Academy of Berlin, a
new method of making a considerable quan-
tity of phofphorus more readily than had
been done before his time. According to his
procefs, the plumbum corneum remaining
after the diflillation of four pounds of mi-
nium and two pounds of fal-ammoniac, is
mixed with ten pounds of the extract of
urine of the confiftence of honey; half a
pound of charcoal in powder being added, the
mixture is dried in an iron pot till it is con-
verted into a black powder; this powder
is diflilled in a retort, to obtain, by a gra-
dual fire, the volatile alkali, fetid oil, and
fal-ammoniac. Care muft be taken to urge
the fire no more than till the retort is mo-
derately red. The black and friable matter
of this diflillation is that which affords the
phofphorus ; it is affayed by throwing a
fmall quantity on heated coals ; if it emits
a fmell of garlick, and a blue phofphoric
flame, it is a proof that it has been well pre-
pared. An earthen retort of HefTe or of Pi-
cardy, is rilled to three-fourths of its capa-
city with this fubflance, well coated with
lute ; this veffel is placed in a reverberatory
A a 3 furnace,

374 PHOSPHORUS.

furnace, with a dome and iron chimney of
fix or eight feet in height ; a middle-fized
receiver, pierced with a fmall^perforation,
and half rilled with water, is to' be adapted,
and the place of junction muft be luted with
fat lute, covered with fillets dipped in white
of egg and lime; a brick wall is built up be-
tween the furnace and the receiver, and the
whole apparatus is then left to dry for a
day or two. The diftillation is then be-
gun, by a fire very gradually raifed, and
the operation lafts from fix, to eight or
nine hours, according to the quantity of
matter expofed to diftillation. The phof-
phorus is rectified by re-diftillation by a very
gentle heat, in a retort of glaft, with a re-
ceiver half filled with water. Moil chemifts
have repeated the procefs of Margraaf with
fuccefs ; and it was the only procefs ufed,
till the late difcovery of fepirating the phof-
phoric acid from bones, as we ihall obferve
when we come to fpeak of thefe organs.

It may be obferved, that the procefs of
Margraaf differs from that of Hellot only in
the addition of the plumbum corneum, and
the dividing the operation into two; but
the rhoft valuable part of the operation of
the learned chemift of Berlin, coniifts in his
determining which of the fubftances con-
tained in urine fervts to form the photpho-
rus. By diftillation of a mixture of the fu*
fible fait and charcoal, he obtained a very

fine

phosphorus. 375

fine phofphorus, and obferved that urine,
from which this fait has been extracted, af-
fords fcarcely any of this combuftible fub-
ftance. It therefore follows, that phofpho-
rus is formed by means of one of the con-
flituent parts of fufible fiilt ; and this fub-
fiance is eafily obtained, by diftilling two
parts of the glafs obtained by this fait, de-
compofed in a retort or a crucible, with one
part of charcoal in powder. This operation
requires much lefs time, and a lefs degree of
heat, than thofe we have before defcribed,
fince, according to M. Prouft, the phof-
phorus comes over at the end of a quarter
of an hour. It is doubtlefs the beft procefs
for procuring the phofphorus of urine ;
but feveral objections may be made to it :
I. The vitreous refidue of the decompo-
fition "of the ammoniacal phofphat by fire,
not being the pure phofphoric acid, but
combined with phofphat of foda, which
is not decompofable by charcoal, the quan-
tity of phofphorus obtained by employ-
ing this refidue is but very fmall ; fince an
ounce affords no more than a drachm, and
frequently a lefs quantity. 2. Becaufe,
when a large quantity of fufible fait is ob-
tained by evaporation and cooling, it is
found to be mixed with a great quantity
of the phofphat of foda, which does not
afford phofphorus. It may from thefe two
obfervations, be conceived why fo fmall a
A a 4 quan-

37^ PHOSPHORUS.

quantity of this combuftible fubftance is
obtained by the diftillation of fufible fait
with charcoal : fufible fait alone, of the
mixture of the ammoniacal phofphat and
phofphat of foda, diitilled with charcoal and
muriate of lead, or plumbum corneum, may
perhaps afford a larger quantity, fince the
latter appears to have the property of decom-
poling phofphat of foda.

Phofphorus obtained by all the pro-
ceffes we have defcribed, is always the
fame fubftance. When very pure it is tranf-
parent, and of a confidence refembling that
of wax ; it cryftallizes, by cooling, in la-
minae, which are brilliant, and as it were
micaceous ; it melts in hot water, long be-
fore the fluid becomes boiling hot ; it is
very volatile, and by a gentle heat rifes and
comes over in the form of a thick fluid.
When in contact with air, it emits a fume
from every part of its furface j and this va-
pour, which fmells ftrongly like garlick,
appears white in the day-time, but is very
luminous in the dark. The flow combuftion
of phofphorus confifts in this difengagement,
and if it be left for a certain time exp><fed to
the air, it confumes by degrees, and leaves
a peculiar acid, whofe picperties we (hall
hereafter examine. Thi* flow combuftion can-
not be performed, unlels the phofphorus be
in contact with the air ; and in order that it
may be very luminous, a heat of from twelve •

to

phosphorus. 377

to fifteen degrees of Reaumur's thermometer,
or about fixty-three degrees of Fahrenheit's,
is required, though it takes place at a lower
temperature. The inflammation does not
produce heat, nor fet any combuftible body
on fire ; but when phofphorus is expofed
to a dry heat, of twenty-four degrees of
Reaumur, or eighty-fix of Fahrenheit, it
takes fire with decrepitation, burns rapid-
ly, with a very lively white flame, mixed
with yellow and green, and deftroys all the
combuftible bodies it touches with the great-
eft facility. The vapours it emits are then
very abundant, white, very luminous in the
dark, and leave a different refidue in each of
thefe combuftions : the firft affords a liquor,
which weighs more than twice as much as the
phofphorus made ufe of, and is known by
the name of the phofphoric acid : the fecond
leaves a thick matter, of a reddifh white,
which emits white vapours, till it has at-
tracted a furlicient quantity of the moifture
of the air to become fluid ; it then refembles
the acid and fluid refidue of the firft com-
buftion, or flow inflammation ; yet thefe
two acids prefent certain differences in their
combinations, as Margraaf has obferved, and
as M. Sage has likewife pointed out, in the
Memoirs of the Academy for the year 1777.
We (hall fpeak more fully refpefting thefe
differences in the hiftory of the phofphoric
acid. '

The

378 PHOSPHORUS.

The combuftion of phofphorus was con-
fidered by Stahl as the di fen gage me lit of
phlogifton, which he fuppofed to be com-
bined with the muriatic acid * in this in-
flammable fubftance. M. Lavoifier, in or-
der to difcover what happens in this com-
buftion, burned, by the concentrated rays
of the fun, phofphorus under a glafs veffel,
inverted over mercury ; he obferved that, no
more than a certain quantity can be burnt
in a determinate bulk of air, and that this
quantity coniifts of one grain of phofphorus
for fixtcen or eighteen cubic inches of air ;
that after this combuftion, the phofphorus
is extinguifhed, and the air is no longer
capable of burning new phofphorus ; that
the volume of the air is diminimed, and the
phofphorus diffipated in white fnowy flakes,
which adhere to the fides of the veffel. Thefe
flakes are twice and a half the weight of the
phofphorus ufed, and this augmentation of
weight correfponds exactly to that which
the air has loft, and depends intirely on the
abforption of the oxyginous principle by the

* Stahl has affirmed in feveral of his works, that by
combining the marine acid with phlogifton, phofphorus
may be made. Margraaf made a feries of experiments
with different combinations of the marine acid, treated with
combuftible bodies, and never fucceeded in producing phof-
phorus ; he has likewife fhewn, that the acid which re-
mains after the combuftion of this fubftance differs very
much from that of marine fait ; and this is at prefent uni-
verfally admitted by all chemifts. Note of the Author.

phof-

phosphorus. 379

phofphorus : in fad:, the white flakes are
the concrete phofphoric acid, formed by the
combination of phofphorus with the portion
of pure air contained in the atmofpheric air,
which has ferved to burn this inflammable
fubitance. This theory is the fame as that of
fulphur, and it is therefore unneceffary to
repeat what has been faid refpedting this fub-
fiance in the mineral kingdom.

If phofphorus be liquified in hot water,
and vital air be parTed through it under water,
it burns, and is reduced to the flate of phof-
phoric acid.

Though phofphorus be not foluble in
water, yet it is changed by it in procefs of
time, and lofes its tranfparency ; becomes
yellow, and covered with an efflorefcence
and coloured powder ; the water becomes
acid, and appears luminous when agitated
in the dark; the phofphorus is therefore
flowly decompofed.

The cauitic fixed alkalis di Solve phofpho-
rus, by the afliftance of a boiling heat; dur-
ing this combination, a fetid gas, difcovered
by M. Gengembre, which has the Angular
property of taking fire and exploding, by
the con tad: of atmofpheric air, and ftill more
readily by the contact of vital air, is difengag-
ed : this elaitic fluid confifts of phofphorus
diffoived in inflammable gas.

The vitriolic acid, diffoived with phof-
phorus in a retort, decompofes it almofr. in^

tirely,

380 PHOSPHORUS.

tirely, but without inflammation ; the con-
centrated nitrous acid attacks it with vio-
lence, and fuddenly inflames it. When this
experiment is made in a retort, with nitrous
acid not very concentrated, the phofphorus
burns by degrees, feizes the oxyginous prin-
ciple of the nitrous acid, and forms the
phofphoric acid. This procefs was defcribed
by M. Lavoifier in 1780.

The muriatic acid, though fuper-faturated
with vital air, does not attack phofphorus.

Nitrous falts inflame it with great rapi-
dity, by the afiiftance of a low heat.

Sulphur and phofphorus combine, accord-
ing to Margraaf, by fufion and diftillation,
and compofe a folid fubftance, of an hepatic
odour, which burns with a yellow flame,
fwells in water, to which it communicates
acidity, and the fmell of liver of fulphur ;
properties which certainly fhew a peculiar
re-action between thefe two bodies.

Phofphorus does not unite fo readily with
metals as fulphur does, though it refembles
that fubftance in many of its properties.
Margraaf attempted to make thefe combi-
nations, by diftilling the feveral metallic
fubftances, each with two parts of phofpho-
rus : no peculiar phenomena were prefented
but by arfenic, zink, and copper ; all the
other metals were not changed by the phof-
phorus, which was partly burnt or fub-

limcd

PHOSPHORUS. 381

limed in the receiver, without having expe-
rienced any remarkable change.

Phofphorus, fublimed with arfenic, af-
forded this celebrated chemift a fubftance of
a beautiful red, fimilar to realgar.

Zink, diftilled twice fucceffively with this
combuftible fubftance, afforded yellow, point-
ed, and very light flowers ; thefe flowers ex-
pofed to the fire under a red-hot muffle,
burned and afforded a tranfparent green glafs,
fimilar to that of borax.

Copper, treated in the fame manner with
phofphorus, loft its brilliancy, and became
very compact ; its weight was increafed ten
grains in the half drachm, and it took fire,
and burned, on being applied to a flame.

The Marquis de Bouillon and M. Sage have
defcribed a remarkable alteration which phof-
phorus undergoes in metallic folutions : the
firft of thefe chemifts has difcovered, that
fmall fticks of phofphorus, plunged in folu-
tions of gold, iilver, copper, &c. became
gradually covered with a kind of fheath of
fhining metal : thefe valuable experiments
(hew that the phofphorus has a ftronger
affinity with the oxyginous principle than
many metals, and is capable of reducing
their calces. Bergman has eftablifhed the
fadl, that the arfenical acid becomes black,
and is converted to the ftate of metallic arfe-
nic, when heated with phofphorus, which
becomes phofphoric acid, in proportion as

it

382 PHOSPHORUS.

it takes the oxyginous principle from the
arfenic.

Phofphorus diffolves in all oils, and ren-
ders them luminous. Spielman has difco-
vered that it diffolves in fpirit of wine, and
that this folution emits fparks when it is
poured into water : part of the phofpho-
rus is precipitated in a white powder during
this operation.

Phofphorus is not yet ufed either in me-
dicine or in the arts. Meffrs. Menzies,
Morgenftern, Hartman, &c. affirm, that
they have experienced very happy effects in
malignant and bilious fevers, when the
ftrength has been exhaufted, and in the
miliary fever; others have recommended it
in the fcarlet fever, the peripneumony,
rheumatic pains, epilepfy, &c. ; but though
feveral diflertations have already appeared in
Germany on the medical virtues of phof-
phorus employed internally, nothing can
yet be eftablifhed concerning it, till expe-
rience has afcertained its virtues with greater
certainty.

CHAP.

PHOSPHORIC ACID. 383

CHAP. XIX.

Concerning the Phofphoric Acid.

^TpHE phofphoric acid has been thus call-
-■- ed, becaufe it has been thought to exift,
ready formed, in phofphorus, from which it
was obtained by combuftion ; but M. Lavoi-
fier has proved, that this fait is a combination
of phofphorus with the bafe of pure air, or
the oxyginous principle. To obtain this acid,
four proceffes may be ufed : the firft coniifts
in burning phofphorus rapidly, under glafs
verTels filled with atmofpheric air, inverted
over mercury ; the combuftion being begun,
either by a burning glafs, or a red-hot iron
wire; it is neceffary firft to moiften the in-
fide of the glafs with a fmall quantity of
water. This procefs, dire&ed by M. La-
voifier, affords phofphoric acid in a very
fhort time, but mixed with a fmall quantity
of phofphorus, not decompofed : vital air
may be ufed for this combuftion, but the
inflammation is then fo rapid and violent,
that it often caufes the glaffes to fly in pieces.
The fecond procefs, invented by Meffrs.
Wolfe and Pelletier, is performed by paffing
a current of vital air through phofphorus

melted

384 PHOSPHORIC ACID.

melted under water. In the third method,
contrived by M. Lavoifier, phofphorus is
burnt, by means of the nitrous acid, rather
more than moderately ftrong.

The fourth procefs, or flow combuftion,
improperly called the formation of the phof-
phoric acid per deliquium, is very well de-
fcribed by M. Sage. Sticks of phofphorua
are placed in a glafs funnel, whofe neck is re-
ceived in a bottle, and its bafe covered, but
not clofely ; a tube of glafs is put into the
neck of the funnel, in order to prevent the
phofphorus from falling through ; and to
give a paflage to the air of the veflel, dis-
placed by the phofphoric acid, care mull be
taken that the flicks of phofphorus do not
touch each other, and that the temperature
of the place does not exceed fixty degrees ;
as without thefe precautions, the phofphorus
may deflagrate : by this method, an ounce
of phofphorus affords three ounces of an
acid, which is collected in the bottle, with
a fmall quantity of water, added by a little
at a time.

Thefe four proceffes afford the phofphoric
acid in two different ftates, accordingly as
it contains phofphorus not decompofed, or
intirely burnt, and faturated with the oxy-
ginous principle. Thefe two acids exhibit
phenomena, with refpedt to each other, fi-
milar to thofe exhibited by the vitriolic and
fulphureous acids : this is the reafon of the

fmall

PHOSPHORIC ACID. 385

fmall difference between the refults obtained
by MefT. Sage and Lavoifier, in the combi-
nations of this acid, as related in the Me-
moirs of the Academy for 1777. They may-
be brought into the fame ftate of purity by
diftillation with fpirit of wine, which takes
away the portion of phofphorus they may
contain.

The phofphoric acid, obtained by the flow
combuftion, contains but a very fmall quan-
tity of unburnt phofphorus : it is a co-
lourlefs fluid, without fmell, of an acid
tafte, and reddens the fyrup of violets : when
expofed to the action of fire in a retort,
pure phlegm comes over, the acid becomes
concentrated, and heavier than even the vi-
triolic acid, and gradually grows folid, white,
and foft, like an extract. Laftly, when
urged by a violent heat, it melts into a tranf-
parent, hard, very elaftic and infoluble glafs,
which no longer prefents the acid character,
and is by M. de Morveau confidered as a
pure acidifiable bafe : but it is difficult to
admit this opinion, becaufe vital air is not
difengaged during the fufion. This folid and
vitreous ftate appears to depend on a more
intimate combination between the acidifiable
bafe and the oxyginous principle ; and the
want of acidity in this glafs is no more to
be wondered at, than the privation of its
acid property, which the muriatic acid fuf-
fers by combination with an excefs of the

Vol. IV. B b oxyginous

386 PHOSPHORIC ACID.

oxyginous principle. This idea refpe&ing
the more intimate fixation of the bafe of air
in the acidifiable bafe of the phofphoric acid,
is confirmed by the difficulty of obtaining
phofphorus from it by the addition of char-
coal, and by the neceflity of giving a high
temperature to the mixture for that purpofe.

If the phofphoric acid, obtained either
by deflagration, or by the flow combuftion of
phofphorus, be heated in an open veflel,
fmall flames arife, from time to time, which
doubtlefs are produced by a portion of phof-
phorus not yet intirely burned. In thefe
circumftances, the acid becomes concen-
trated and dry, and at laft melts, in the fame
manner as when treated in a clofe veflel.

The concentrated phofphoric acid very
quickly attracts the moifture of the air ; it
unites to water with heat, combines with a
great number of fubftances, and prefents
peculiar phenomena in thefe combinations.

The phofphoric acid does not appear to
a£t on quartzofe earth, neither by the dry
nor the humid way, according to the expe-
riments of Bergman and De Morveau ; but
it acts on glafs, as appears from the experi-
ments of Ingenhoufz and Prieftley. When
urged by the blow-pipe, together with clay, it
boils ; and the phofphoric acid, melted in
Heflian crucibles, gives them a vitreous
tranfparent glaze, as M. de Morveau remarks.

It unites with ponderous earth, and ap-
pears

PHOSPHORIC ACID. 387

pears to prefer it to all other bafes, except
lime, according to Bergman's table of at-
tractions. The properties of barytic phof*
phat are not yet known.

The phofphoric acid diffolves cretaceous
magnefia with effervefcence ; the fait it
forms with this fubftance is of difficult fo-
lubility; a well faturated folution, after
twenty-four hours repofe, affords cryftals in
very flender, fmall, flat needles, feveral lines
in length, and obliquely cut off at each end ;
when expofed to a gentle heat, they become
reduced to powder : the vitriolic acid de-
compofes this fait, according to Lavoifier.

The phofphoric acid, poured into lime-
water, precipitates it in the form of a fait
fcarcely at all foluble, which does not effer-
\cfcQ with acids, and in which the acid is
always predominant: this fait reddens blue
paper, is decompofed by the mineral acids, and
even by the can flic fixed alkali, and affords,
Xvith the nitrous folution of filver, a precipi-
tate of the colour of wine lees -, and with that
of mercury, a white pulverulent precipitate.
This fait is of the fame nature as the refidue
of burned bones. An excefs of the phofphoric
acid renders the calcareous phofphat foluble in
water; but it is precipitated by magnefia, lime,
cauftic fixed alkali, and even by the volatile al-
kali, all which deprive it of its excefs of acid.
The calcareous phofphat is not decompofed
by cauftic alkalis, though it is by the fame
alkalis combined with fixed air.

B b 2 The

388 PHOSPHORIC ACID,

The phofphoric acid, faturated with vege-
table alkali, forms a very foluble fait, which,
by evaporation and cooling, affords tetrahedral
cryftals terminated by four-fided pyramids,
whofe fides correfpond with thofe of the
prifms : this phofphat of pot-am is acid,
and diffolves much more completely in hot
than in cold water ; it expands on hot coals,
and melts but with difficulty ; when melted,
it lofes its faline tafte ; it precipitates the ni-
trous folution of filver, of a white colour,
and that of mercury of a yellowifh white :
it is decompofed by lime-water, which has a
ftronger affinity than the vegetable alkali to
the phofphoric acid.

The mineral alkali, united with the phof-
phoric acid, produces a fait of an agreeable
tafte, fimilar to that of the muriate of foda,
or common fait. The phofphat of foda
does not cryftallize ; it is reduced, by eva-
poration, into a gummy deliquefcent mat-
ter, tenacious and adhefive, like turpen-
tine. This fait was prepared by M. La-
voifier, with the acid obtained by the de-
flagration of phofphorus. M. Sage affirms
that the fait prepared with the acid of phof-
phorus, obtained by the flow combuftion,
and combined with foda, affords cryftals
which are not deliquefcent.

Ammoniacal phofphat, formed by the
combination of the phofphoric acid with the

volatile

PHOSPHORIC ACID. S^9

volatile alkali, is more foluble in hot water
than in cold ; and by cooling affords cryf-
tals, which, according to M. Lavoifier, re-
femble thofe of alum. This fait muft differ
from that obtained from evaporated urine,
becaufe the latter always contains a fmall
quantity of the phofphat of foda.

The phofphoric acid decompofes the vi-
triolic, the nitrous, and the alkaline muri-
ates, by the dry way, and difengages their
acids, by reafon of its fixity ; but it yields
its bafes to them by the humid way.

The phofphoric acid, in its fluid ftate,
a&s only on a fmall number of metallic
fubftances : it readily diflblves zink, iron,
and copper ; thefe folutions do not afford
cryftals by evaporation, except that of
iron, which appears capable of crystalliz-
ing; the others are reduced into dudtile and
foft maffes, refembling extracts : if they be
urged by heat, they throw out fparks, and
appear to form true phofphorus. Margraaf
and the academicians of Dijon have exa-
mined fully the adtion of this acid on metals
and femi-metals.

The phofphoric acid likewife precipitates
certain metallic folutions ; fuch as thofe of
mercury, filver, and lead, by the nitrous
acid.

This acid re-afts on oils, and exalts their

fmell ; to fuch oils as have no fmell it gives

B b 3 a fweet,

390 PHOSPHORI.C ACID.

a fweet and as it were ethereal fmell; it
thickens ibme oils.

When diftilled from charcoal, in its dry
ftate, it affords phofphorus.

When heated in a retort with fpirit of
wine, it afforded the academicians of Dijon a
liquor ftrongly acid, of a penetrating and dis-
agreeable fmell, which burnt with a fmall
quantity of fmoke, and exhibited fome of
the properties of ether. The phofphoric
acid was rendered volatile in this experi-
ment, as appears from the acidity of the
product. M. Lavoiiier has obferved, that
heat is produced in this mixture; yet moil
chemifts coniider the phofphoric acid as
infoluble in fpirit of wine. Margraaf,
Rouelle, Scheele, Wenzell, Laffone, Cor-
nette, and the Due de Chaulnes, have di-
rected the ufe of fpirit of wine to purify
and feparate the phofphoric acid from the
different foreign fubfiances it may contain.
Laftly, the phofphoric acid diifolves the
phofphat of foda, forming with it a kind
of triple fait, which by fulion affords a hard,
iniipid, infoluble, non-deliquefcent, and
opake glafs, fimilar to that afforded by fu-
fible fait alone, when urged by the fire.

We muft likewife obferve, that the phof-
phoric acid, which was formerly fuppofed
to be peculiar to urine, exifts in many ani-
mal matters, as we have already fttn9 and
will hereafter be pointed out. Margraaf

difcovered

PARTS OF ANIMALS. 39I

difcovered it in vegetables, and M. Ber-
thollet has found it in all thofc which afford
volatile alkali by diftillation. It has been
found in many minerals, and in particular
in lead and iron, in which it feems to have
been afforded by the decompofition of ani-
mal fubftances.

This acid has not yet been applied to any
ufe; it might be, perhaps, medically ufed
with fuccefs, on account of its analogy with
animal matters.

CHAP. XX.

Concerning the foft and white Parts of
Animals and their Mufcles.

ALthough the analyfis of the folid parts
of animals be lels advanced than that
of their fluids, yet we begin to acquire
fome knowledge of the different matters
which compofe them ; it more efpecially
afcertained that the difference between their
texture or formation indicates a difference in
their principles. This affertion will be con-
firmed by an examination of the foft and
white parts, and alio of the mufcles and
bones.

All the foft and white parts of animals,
B b 4 fuch

392 PARTS OF ANIMALS.

fuch as the membranes, the tendons, the
aponeurofes, the cartilages, the ligaments,
the Ikin, contain, in general, a mucilaginous
fubftance very foluble in water, and not at
all foluble in fpirit of wine, which is known
by the name of jelly. To extract this jelly,
the animal parts muft be boiled in water,
and the decoction evaporated till it becomes
a folid and tremulous mafs by cooling; a
ftronger degree oi evaporation affords a dry,
brittle, tranfparent fubftance, known by the
name of glue.

G)ue is prepared with all the white parts
of animals; the fkin, the cartilages, and the
fat of oxen, are ufed to prepare the ftrong
glue of England, Flanders, Holland, &c.
The fkins of eels afford the bafe of gold fize,
&nd with old white leather gloves and parch-,
ment, a kind of glue ufed by painters, &c.
is made. There are fcarcely any animals,
whofe tendons, cartilages, nerves, and more
efpecially the fkin, will not ferve to prepare
thefe different kinds of glue.

It muft be here obferved, that glues differ
from each other in their confiftence, tafte,
fmell, and folubility : there are fome which
readily become foft in cold water, others
are not diffolved but in boiling water. The
beft glue is tranfparent, of a yellow brownifh
colour, without fmell and tafte, intirely
foluble in water, with which it forms a
yifcid uniform fluid that preferves an equal

degree

PARTS OF ANIMALS. 393

degree of tenacity and tranfparency in all its
parts as it dries.

Animal jelly does not differ from glue
properly fo called, but in its poifeffing a lefs
degree of coniiftence and vifcidity. The firft
is more efpecially obtained from the foft and
white parts of young animals ; it is likewifc
found in their flefh, tnufcles, fkin, and
bones. Glue is obtained only from ani-
mals of a greater age, whofe fibres are
ftronger and drier. Thefe two lubftances
however, exhibit the fame chemical pro-
perties ; and therefore we (hall fpeak of the
jelly afforded by the cartilages or membranes
of veal.

In its natural (late, jelly has no fmell,
and but a faint tafte : by diftillation in the
water- bath, it affords an infipid and inodo-
rous phlegm, capable of putrefaction ; in
proportion as it lofes its water, it affumes
the confidence of glue, and when intirely
dried, it refembles horn ; when expofed to
a ftronger fire, with accefs of air, it fwells,
liquifies, and becomes black, emitting an
abundant fume of a fetid fmell -y it does not
take fire without difficulty; and by a vio-
lent heat by diftillation in a retort, it affords
an alkaline phlegm, an empyreumatic oil,
and a fmall quantity of ammoniacal chalk ;
it leaves a large mafs of charcoal, difficult
to incinerate, which contains muriate of
foda, and calcareous phofphat.

Jelly,

394 PARTS OF ANIMALS.

Jelly, when expofed to a hot and moid
air, becomes firft acid, and foon after putrid.

Water diflblves it in all proportions ;
acids, and efpecially. alkalis, diffolve it rea-
dily ; the nitrous acid difengages mephitis.
Moft of thefe properties fliew a refemblance
between jelly and the infipid vegetable mu-
cilages, if we except thofe of affording vo-
latile alkali by heat, and mephitis by the
nitrous acid : and may not thefe laft be at-
tributed to a portion of lymphatic matter
or ferum, which the water extracts at the
fame time with the gelatinous fubftance,
efpecially when jellies or glues have been
prepared by ftrong decoction long conti-
nued ?

The mufcles of animals are formed of a
parenchymatous and cellular fubftance, in
which different humours are contained, partly
concrete, and partly fluid. Thefe humours
are compofed, I. Of a red and white fluid.
2. Of a gelatinous mucilage. 3. Of a mild
oil, of the nature of fat. 4. Of a peculiar
extractive fubftance. 5. Laftly, of .a faline
matter, whofe nature is but little known.
The analyfis of flefh, when diflilled in a
water-bath, affords an infipid water ; and in
a retort an alkaline phlegm, an empyreumatic
oil, and concrete volatile alkali ; and which
leaves a charcoal, from which a fmall q-uantity
of fixed alkali, and febrifuge or marine fait,
are obtained by incineration : thefe properties

difcover

PARTS OF ANIMALS. 395

difcover nothing which can be depended
on reflecting the nature of the principles.
It is therefore neceflary to have recourfe to
methods, by which thefe fubftances may-
be extracted without alteration, and after-
wards examined feparately.

M. Thouvenel, who fir it obferved thefe dif-
ferent fubftances, forced out the fluids contain-
ed in the mufcular fpunge by preiiure, coagu-
lated the lymph by the action of heat, and ob-
tained the fait by evaporation. Hediftilledand
feparated the gelatinous mucilage by means of
water, and ufed fpirit of wine to feparate the
falts and extract from the jelly. The accurate
feparation of thefe different matters is, in
general, very difficult ; becaufe they are all
lbluble in water, and fpirit of wine diifolves
the faponaceous extract, and a part of the
fait at the fame time. The procefs which
fucceeds beft, appears to be the following :
The flefh is firft warned in cold water, which
takes up the colouring lymph with a part of
the fait; the refidue being digefted in fpirit
of wine, gives out all the extractive matter,
and a portion of fait to that menftruum.
Laftly, the remaining mafs being boiled
in water, gives out its gelatinous part,
and likewife .thofe portions of extract and
fait, which efcaped the action of the former
menftrua. By flowly evaporating the water
firft employed, without heat, the lymph coa-
gulates, and is feparated by the filter, and

the

396 PARTS OP ANIMALS.

the faline matter may be obtained by a fuc-
ceeding evaporation ; the fpirit of wine
like wile being evaporated, affords the co-
loured extractive matter ; and laftly, the
decoction affords the jelly and the fat oil
which fwims at the furface, and fixes by
cooling. After the extraction of thefe dif-
ferent fubftances, nothing remains but the fi-
brous matter, which is white, infipid, infolu-
ble in water, contracts and curls up by heat;
and by diftillation in a retort, affords much
volatile alkali, and a very fetid oil. A large
quantity of mephitis is obtained from this
fubftance by the action of nitrous acid. In a
word, it poffeffes the characters of the fibrous
part of the blood -y it therefore appears to
be proved, that the mufcular organ is the
refervoir, in which the action of the vital
powers depofits the fibrous matter, which
becomes concrete by reft; and which ap-
pears to form the bafis of that animal pro-
perty which phyfiologifts call iiritability.

Nothing remains now, but to examine
the properties of each of the fubftances of
which the flefti of animals are compofed, in
order to afcertain its nature with accuracy.

The lymph, the jelly, and the fat part
are already known ; the fir ft ^perfectly re-
fembles the ferum of blood. AVe muft ob-
ferve, that it is this fubftance, which coagu-
lating by the heat of water, in which animal
food is boiled, produces the fcum which i$

carefully

PARTS OF ANIMALS. 397

carefully taken off. This fcum is of a dirty
red brown, becaufe the red lymph is altered
by the heat of ebullition. The jelly extracted
from flefh caufes foups, prepared with the
flefh of young animals, which contains it in
greater quantities than that of older animals,
to affume the form of a tremulous mafs. It
is abfolutely fimilar to that which confti-
tutes the foft and white parts of animals,
whofe properties have been explained in the
preceding article. The fat fubftance which
forms the flat and round drops that float on
the furface of broths and foups, and become
folid by cooling, has all the characters of
greafe. It only remains, therefore, to exa-
mine the extractive matter, and the folid,
obtained in the analyfis of the mufcles.

That which M. Thouvenel calls the
mucous extractive fubftance, is foluble in
water, and fpirit of wine ; it has a ftrong
tafte, whereas jelly has none. When it is
very concentrated, it is acrid and bitter; and
it has a peculiar aromatic fmell, which fire
developes. This fubftance gives the colour
to foups, as well as the tafte and agreeable
fmell which are well known. When they
are too much evaporated, or the quantity of
flefh is very gpnfiderable in proportion to the
water, foups\ are high coloured, and more
or lefs acrid. . The action of fire developes
and exalts the tafte of this extractive fub-
ftance, fo as even to give it the tafte of fugar,

or

39§ PARTS OF ANIMALS.

or caramel, as is obferved on the furface of
roaft meat, which is commonly called the
brown . If we further examine the properties
of this extractive fubftance when evaporated
to drynefs, we obferve, that its tafte is acrid,
bitter, and ialine ; that it fwells and liqui-
fies on hot coals, emitting a penetrating acid
fmell, fimilar to that of burnt fugar ; that it
attracts moifture when expofed to the air, and
acquires a faline efflorefcence on its furface ;
that it becomes four, and putrefies in a warm
air, when diluted with a certain quantity of
water ; and laftly, that it is foluble in fpirit
of wine. All thefe characters indicate a re-
femblance between this acid and the fipo-
naceous extracts, and faccharine matter of
vegetables.

The nature of the fait which cryftallizes
in the flow evaporation of the decoction of
flefh, is not yet perfectly known. M. Thou-
venel obtained it in the form of down, and
that of irregular cryftals. This chemift
thinks that it is a perfectly neutral fait,
confiuing of pot-afh, and an acid which has
the character of the phofphoric acid in fru-
givorous quadrupeds, and that of the muri-
atic acid in carnivorous reptiles. Though this
fait may be confideredas unknown, tiil afuf-
ficient quantity (hall have been collected, to
admit of its being examined with accuracy ;
yet it is very probable that it conlifts of the
phofphoric acid, combined with the mineral

and

PARTS OF ANIMALS. 399

and vegetable alkali, and mixed with calca-
reous phofphat. Thefe falts are indicated
even with excefs of acid, as in urine, by the
teft of lime-water and volatile alkali, which
form white precipitates in the decoftion ;
and the nitrous folution of mercury, which
affords a rofe-coloured precipitate with the
fame liquor.

We may likewife add, that the moft a-
bundant fubflance, and that which confti-
tutes the proper character of mufcular flefti,
is the fibrous part. This matter is depofited
bv the blood, which contains it in a large
proportion, and appears to be of great import-
ance in the animal economy. Its nature and
properties have not been fufficicntly attended
to in phyfiological inquiries refpedting the
quantity and weight of mufcular flem com-
pared with the ether organs. The characters
which diitinguifh this animal matter are, 1.
That it is not foluble in water. 2. It affords
a larger quantity of mephitis by the nitrous
acid, than any other fubftance. 3. It after-
wards affords the faccharine acid, and that
which M. de Morveau calls the malufian
acid. 4. It quickly putrefies when moiftened,
and affords much concrete volatile alkali by
diftillation.

Thefe properties {hew, that it is formed
by a fat or oily fubftance combined with
mephitis, together with the phofphat of
foda, and the calcareous phofphat, which

are

400 BONES*

are feparated by the action of the nitrous
acid. I have considered the purpofes which
are anfwered in the animal economy by this
fibrous matter, in a particular Memoir in-
ferted among thofe of the Royal Society of
Medicine.

T

CHAP. XXL

Concerning the Bones of Animals.

HE bones are the fupport of all the
other organs of animals, the bafes on
which all the foft parts reft. Thefe hard
fubftances cannot be confidered as paffive in
the animal economy, they are true fecretory
organs, which feparate from the blood and
other humours a peculiar faline fubftance,
of which they are the refervoir, or place of
depofition.

The bones in all animals, from man to
infedts and worms, differ in their texture,
folidity, relative pofition, and probably in
their nature. Chemical analyfis has not yet
decided refpecling this lafl point ; but it can
hardly be fuppofed, that the bones of men
and quadrupeds are of the fame nature as the
foft; and flexible bones of fifties, reptiles,
and more efpecially the corneous coverings

of

BONES. 40X

of infedts, as well as the calcareous fhells of
reptiles.

The general view which we {hall here
take of the bones of animals, does not per-
mit us to dwell on fuch differences as che-
mifts have not yet fufficiently afcertained by
experimental inquiry. The bones of men
and of quadrupeds, which alone have been
hitherto examined by chemifts, are not ear-
thy matters, as was formerly fuppofed : they
contain a certain quantity of gelatinous mat-
ter, difperfed in fmall cavities, formed by
the interval between the folid parts which
compofe their texture; and the folid parts
themfelves, though they feem to refemble
earthy fubftances by their infolubility and
iirmnefs, have been for feveral years paffc
acknowledged to be a true neutral fait, con^
lifting of phofphoric acid and lime.

Bones expofed to fire with the contact of
air, quickly take fire, by virtue of a certain
quantity of medullary fat which they contain.
By diftillation in a retort, they afford an alka-
line phlegm, a fetid empyreumatic oil, and
much concrete volatile alkali : their coal is
compadt, and difficultly incinerated, and
leaves a white refidue, which, by warning in
cold water, affords a fmall quantity of cre-
taceous foda ; hot water afterwards takes up
a certain quantity of felenite : the refidue of
thefe lixivia is infoluble in water, and is
Vol, IV C c the

402 BONES.

the calcareous phofphat difcovered by M.
Gahn of Stockholm, in 1769. Bones cal-
cined in a furnace in the midft of the char-
coal, remain luminous in the dark: byaftrong
heat they are femi- vitrified and reduced into
a hard very white kind of porcelain.

Water, in which bones, reduced into fmall
pieces or rafped, are boiled, becomes loaded
with a fubftance which renders it vifcid, and
is a true gelatinous matter.

The cretaceous alkalies decompofe the
calcareous phofphat, which forms the bafe
of bones. This decompolition was difco-
vered by the chemifls of the academy of
Dijon : they inform us, that they pro-
duced it by fufing a mixture of the powder
of calcined bones, and cretaceous vegetable
alkali.

Acids aft: on bones, and decompofe the
calcareous phofphat they contain; by which
means it was that Scheele, in the year 1771,
fucceeded in preparing phofphorus with
bones. This chemift diflblved bones in the
nitrous acid, which feized the lime, and
formed calcareous nitre \ the fait remaining
in folution, together with the difengaged
phofphoric acid : on this mixture he poured
vitriolic acid, which feizing the lime of the
calcareous nitre formed felenite ; this fait
being precipitated on account of its infolu-
bility, was Separated by the filter. Laftly, he

diftilled

BONES* 463

diftilled in a retort the filtered liquor con-
taining the nitrous and phofphoric acids, and
when the latter by the evaporation was re-
duced to the confidence of fyrup, he mixed it
with charcoal, to obtain phofphorus. MefTrs.
Rouelle, Poulletier, dela Salle, andMacquer,
were the firfl who repeated thefe valuable ex-
periments at Paris. Laftly, the Academicians
of Dijon, Meffrs. Rouelle, Prouft, and Ni-
colas de Nancy, communicated their in-
quiries and procefTes. Many other chemifts
have examined the feveral folid fubftances,
and among the latter Mr. Bernierd obtained
phofphoric acid from foffil bones, from the
bones of the whale, the elephant, the por-
poife, the elk, the ox, the teeth of the fea
cow, and the human fpecies, and the grind-
ers of the elephant ; and he obferved that
all thefe bones afforded the fame fubftances*
and contained phofphoric acid in different
quantities. The Marquis de Bullion has
likewife obtained phofphoric glafs from ivory,
and from the bones of fifhes.

The procefs of the chemifts of Dijon and of
M. Nicholas is at prefent moftly ufed to obtain
the phofphoric acid from bones : the bones
are calcined to whitenefs, reduced to dow-
ier, lifted and mixed in a ftone-ware pan,
with an equal portion of oil of vitriol, a fuf-
Bcient quantity of water being added, to give
the whole the confidence of clear foup ; this
mixture being left at reft for feveral hours,
C c 2 grows

4C4 PHOSPHORUS FROM

grows thick; it is then poured on a fil-
ter of double cloth, and warned with wa-
ter, till the fluid which paffes through is
taftelefs, and no longer precipitates lime-
water ; in this cafe it is certain, that the
refidue contains no more difengaged phof-
phoric acid : the filtered water being eva-
porated depofits gradually a white fubftance
which is felenite, and muft be feparated by
a filtration, care being taken to wafh it with
a fufficient quantity of water to carry off
the phofphoric acid that may adhere to it.
Thefe filtrations are to be repeated till the
fluid depofits no more precipitate : it is then
evaporated to the confidence of honey,
or a foft extract, and at that time has
a brown colour and greafy afpedt. If this be
gradually heated in a crucible till it ceafes
to emit a fulphureous, and as it were aro-
matic fmell, and no longer boils, it acquires
a femi-vitreous confidence with an acid tafte,
and attracts the humidity of the air : a greater
degree of heat fufes it into a tranfparent,
hard, infipid, infoluble matter, which has
no acidity. When phofphorus is intended
to be made, it is not neceflary to continue the
heat till the refidue becomes converted into
the form of an infoluble glafs, becaufeit then
would not afford phofphorus, but by a ftrong
heat and much lefs readily, than while it is
Hill foft and deliquefcent, To convert it into

phofphoras

BONES. * 405

phofphorus it is pulverized, mixed with one
third of its weight of very dry charcoal, and
the mixture introduced into an earthen re-
tort, to which a receiver half filled with
water, and pierced with a fmall aperture, or
terminating in a fyphon connected by the ap-
paratus of Woulfe is adapted ; the fire is raifed
by degrees till the retort is heated towhitenefs,
at which time the phofphorus pafTes over ia
drops, and the operation lafts in the whole
from five to kvcn or eight hours, according
to the quantity of the matter diftilled, and
the heat the furnace is capable of giving.
From fix pounds of bones, twenty ounces,
or a little more, of the vitriform refidue is
ufually obtained ; and this refidue affords
about three ounces of very good phofphorus,
and a few drachms of phofphorus half decom-
pofed.*

* It is not necefTary, for the making of phofphorus, to
carry the evaporation farther than till the matter has ac-
quired the ccnfiftence of fvrup, which may be conveniently
performed in a copper veflel ; and inftead of a receiver,
the neck of the retort, may be plunged fimply in water
contained in an open bafon. Care mult, be taken that the
neck of the retort is not plunged fo deep as that the water
may rife into the body of the veflel, when abforption takes
place, but that the fluid in the bafon may by its fall fuffer air
to enter; in this cafe a fmall quantity of the phofphorus within
the neck of the retort may be burned, but the quantity thus
loft is very inconfiderable. Phofphorus is ufually purified by
graining it through a leather bag immerfed in hot water ;
but the beft method of clearing phofphorus from the im-
purities of the firft diftillation, is to rc-diftil it with a very
gentle heat* T.

C c 3 This

406 BONES.

This product obtained from bones by the
vitriolic acid, as well as the refidue of the
ammoniacal phofphat, decompofed by fire,
does not confift of the pure phofphoric acid,
fince it affords at moft one-fifth of its weight
of phofphorus : it appears to contain a cer-
tain quantity of phofphat of foda. If this
fait remains mixed with calcareous phof-
phat, ariling from a fmall quantity of fele-
nite, it ufually melts with the phofphat,
and forms a very hard opake glafs, which
refifts the action of all menftrua.

M. de Morveau has propofed a method of
obtaining very pure ammoniacal phofphat,
with the phofphoric acid of bones ; for this
purpofe, calcined bones muft be diflblved in
the diluted vitriolic acid, and the folution
effayed by that of bones in the nitrous acid,
in order to be fure that no difengaged vitri-
olic acid remains, the portion of calcareous
phofphat it contains is precipitated by the
cauftic volatile alkali, as M. Wiegleb prac-
tifes in his procefs ; after which the liquid
is filtrated, and fufTered to evaporate fpon-
taneoufly. Very beautiful cryftals of am-
moniacal phofphat are obtained, mixed with
a fmall quantity of phofphat of foda, which
feparates by efflorefcence. The calcareous
phofphat, which remains on the filter, may
be decompofed for the making of phof-
phoru5.

CHAP.

ANIMAL PRODUCTS. 407

CHAP. XXII.

Concerning different Subftances ufed -in
Medicine and the Arts, which are ob-
tained from Quadrupeds, Cetaceous Ani-
mals, Birds, and Fifties.

IF we propofed to make an accurate and
ample hiftory of all the fubftances af-
forded by animals, and applied to medical
purpofes, or ufed in the arts, it would oc-
cupy more of our time than has already been
applied to the animal kingdom, more efpe-
cially if we were to treat of the feveral ani-
mal matters, which empiricifm, or ignorant
credulity, have formerly introduced into
medicine as celebrated remedies, but which
at prefent are regarded as intirely ufelefs.
We do not, however, propofe to mention
more than the principal of thefe fubftances,
which medical and chemical experience has
{hewn to poifefs valuable properties, or
which are of the greateft utility in the arts.

Among the matters afforded by quadru-
peds, we feledl cafloreum, mufk, and hartf-
horn. The white fubftance produced by a
cetaceous animal, and known by the name
of fpermaceti, will be treated of apart.
C c 4 Among

408 ANIMAL MATTERS

Among the produces of birds, we (hall ex-
hibit the analyfis of eggs ; among oviparous
quadrupeds and ferpents, the tortoife, the
frog, and the viper will claim a feparate ar-
ticle. Icthyocolla, or ifinglafs, is the only
product of fifties which we fhall confider.
The clafs of infects will afford a greater
number of objects : cantharides, ants, milli-
pedes, honey, wax, the filk worm, and filk,
gum lac, kermes, cochineal, and crabs eyes;
and laftly, we fhall conclude our examina-
tion of the products of the animal kingdom,
by thofe of coral and corallines, which be-
long to the clafs of worms and polypi.

From this fhort enumeration, it will be
feen, that we pafs over in filence a great
number of other matters, formerly ufed in
medicine ; fuch are, among others, ivory,
unicornu, the teeth of the hippopatamus, of
the beaver, of the boar, the bones of a flag's
heart, the feet of the elk, bezoar, civet,
and the blood of the wild goat, among qua-
drupeds ; the fwallow's nefl, goofe greafe,
peacock's dung, and the membrane of the
itomach of poultry, among birds -, the toad,
ana the fcincus among oviparous quadrupeds;
the gall and ftones of carp, the liver of the
eel, the ftones of perch, the jaws of the pike,
among fifhes ; the fear-abacus, fpider's-web,
the meloe, or profcarabaeus, and the claws
of crabs among infects. Laftly, fhell-
\vprms, fnails, oyfter-ihells^ nacre* of pearl,

an4

USED IN THE ARTS, 409

and bones of cuttle-fiih, among the naked,
or covered worms. Among all thefe fub-
fiances, fome have only imaginary virtues,
and others are well fupplied by thofe we
have chofen, and which wre fhall proceed
to examine.

I. The name of caftoreum is given to two
bags, fituated in the inguinal region of the
male or female beaver, which contains a
verv odorous fubftance, foft and almoft fluid
when recently cut from the animal, but
which dries, and afTumes a refinous confif-
tence, in procefs of time. This fubftance
has an acrid, bitter, and naufeous tafte; its
fmell is ftrong,. aromatic, and even fetid ;
it confifts of a coloured, refinous mat-
ter, foluble in fpirit of wine or ether, to-
gether with a gelatinous mucilage, and an
extractive part taken up by water, *and a fo-
lid, which cryftallizes in the aqueous folu-
tion by evaporation, but whofe nature has not
yet been examined. The refin of caftoreum,
in which its whole virtue refides, appears to
be analogous to that of bile. All the Yub-
ftance of this animal product is inclofed in.
membranous cellules, which proceed from
the internal tunic of the bag which contains
them. The caftoreum has not yet been ac-
curately analyzed ; it is only afcertained,
that it affords a fmall quantity of effential
oil and volatile alkali by diftillation, and
that the feveral matters of which it is com-

pofed

4IO MUSK.

pofed may be feparated by means of ether,
fpirit of wine, and water.

It is medicinally ufed as a powerful anti-
fpafmodic in hyfterical and hypochondriac af-
fections, and the eonvulfions which are caufed
by thofe affedtions : it often produces the
moft fpeedy and happy effefts, but it fome-
times happens that it irritates inftead of
calming, according to the difpofition of the
nerves and fenfible fyftem ; it muft for
this reafon be adminiftered at firft only
in fmall dofes : it has likewife been fuc-
cefsfully adminiftered in the epilepfy and
tetanus. The dofe is from a few grains to
half a drachm in fubftance ; it enters into
the compofition of boles, and is often unit-
ed, almoft always advantageoufly, with opi-
um, and the fedative or narcotic extracts ;
its fpirituous and etherial tindlures are like-
wife ufed, from a few drops to twenty-four
or thirty-fix grains, in proper liquids.

II. Mufk is a fubftance, whofe ftrong
and permanent fmell is univerfally known $
it is contained in a bag placed near the
Umbilical region of a ruminating quadru-
ped, refembling the antelope, from which
it does not differ fufficiently to form a
particular genus. This fubftance refem-
bles caftoreum in its chemical proper-
ties ; it confifts of a refin, united to a cer-
tain quantity of mucilage, bitter ex tradt, and
fait -, it is often falfified ; its virtues are

ftronger

HARTSHORN. 41 I

ftronger than thofe of caftoreum; and on
account of its greater activity, it is ufed only
in cafes of imminent danger. It, is pre-
fcribed as a powerful antifpafmodic in con-
vulfive diforders, the hydrophobia, &c. ; atad
is likewife confidered as a violent aphrodi-
fiac. It muft be ufed with great caution, be-
caufe it often excites nervous affections, in-
ftead of mitigating them.

III. Hartmorn is an animal fubflance
which is very frequently ufed in medi-
cine ; it is a bony fubftance, and does
not in any refpect differ from other bones ;
it contains abundance of taftelefs jelly, very
light, and nourishing, which is extracted
by boiling the fubftance, reduced into fmall
pieces, in eight or ten times its weight
of water. When diftilled in a retort, it
affords a reddifh and alkaline phlegm, cal-
led volatile fpirit of hartmorn ; an oil,
more or lefs empyreumatic ; and a large
quantity of ammoniacal chalk, contami-
nated by a fmall quantity of oil ; a pro-
digious quantity of gas is difengaged, for
the moft part inflammable. As the .volatile
fait is coloured, it is neceffary to digeft it in
a fmall quantity of fpirit of wine, which
takes away the colouring oil. The carbona-
ceous refidue being incinerated, is found to
contain a fmall quantity of natrum, felenite,
and much calcareous phofphat, mixed with
phofphat of foda, which may be decom-

pofed

412 hartshorn;

pofed by oil of vitriol, in the manner already
defcribed in treating df bones.

The fpirit and the fait of hartfhorn are
ufed in medicine as good antifpafmodics ;
the firft, faturated with the acid fait of am-
ber, forms the fluid called fuccinated fpirit
of hartfhorn.

The oil of hartfhorn, rectified by a gentle
heat, becomes very white, odorous, vola-
tile, and almoft as inflammable as ether;
it is known by the name of the animal
oil of Dippel, a German chemift, who firft
prepared it. A great number of rectifica-
tions were formerly made to obtain this oil
very white and fluid ; but it has fince been
difcovered, that two or three diftillations are
fufficient, provided care be taken, i. To
introduce the oil into the retort, by means
of a long funnel, in order that the neck of
this veflel may be very clean, as a fingle
drop of the coloured oil is fufficient to give
a tinge to all that comes over. 2. To take
only the firft moft volatile and whiteft por-
tions. We are indebted to Meflrs. Model
and Baume for thefe obfervations. Rouelle
has likewife given a very good procefs for
obtaining this oil : it confifts in diftilling it
with water : and as there is only the moft vo-
latile and truly ethereal part contained in the
oil of the firft diftillation, which is capable
of rifing at the degree of heat of boiling
water, this method is attended with a cer-
tainty of the moft attenuated and penetrat-
ing

SPERMACETI. 413

ing portion .conning over alone. The ani-
mal oil of Dippel has a lively fmell, and a
lingular degree of lightnefs and volatility,
and exhibits all the properties of vegetable
eflential oils, and from which does not ap-
pear to differ, but in containing the volatile
alkali, as appears by its converting fyrup of
violets to a green, according to the obferv-
ation of M. Parmentier. This oil is ufed
in drops, in nervous affections, the epilepfy,
&c.

IV. The white fubftance, improperly
called fpermaceti, is an oily, concrete, crys-
talline, femi-tranfparent matter, taken out
of the cavity of the cranium of the cacha-
lot; it is purified by liquefaction, and the
feparation of another fluid and inconcrefci-
ble oil, with which it is mixed. This fub-
ftance exhibits very fingular chemical pro-
perties ; for it refembles fat oils in fome re-
fpetts, and eflential oils in others.

Spermaceti heated with the contadt of air
takes fire, and burns uniformly without
emitting any difagreeable fmell. It is there-
fore made into beautiful candles at Eayonne,
at St. Jean de Luz, &c.

When diftilled by a naked fire, it does not
afford an acid phlegm like fat oils, as M.
Thouvenel has obferved, but it pafles iritirely,
and almoft without alteration, into the receiv-
er, as foon as it begins to boil, and leaves a
coaly mark in the retort, By repeating this

operation,

414 SPERMACETI. .

operation, it lofes its folid form, and re-
mains fluid without becoming more volatile.
Spermaceti expofed to a hot air, becomes
yellow and rancid, but lefs readily than the
other concrete fat oils. The water in which
it is boiled affords only a light mucilaginous
undtuous refidue.

The cauftic alkali diffolves fpermaceti,
and forms a foap which gradually beeomes
folid, and even friable.

The nitrous and marine acids have no
aftion on it. The concentrated vitriolic
acid diffolves it, and alters its colour. This
folution is precipitated by water, like the
oil of camphor.

Spermaceti unites with fulphur like the
fat oils.

The fat and effential oils diffolve fperma-
ceti by the affiftance of heat ; hot fpirit of
wine likewife diffolves it, and fuffers it to
precipitate by cooling. Ether effects this
folution in the cold, or by the fimple heat of
hand.

Has not fpermaceti the fame relation to
fat oils, as camphor to effential oils?

This fubftance was formerly much ufed in
medicine, a great number of virtues having
been attributed to it; it was more particularly
ufed in catarrhs, ulcers of the lungs, of the
reins, &c. It is not at prefent ufed except as
a foftening remedy, and then in fmall dofes,
mixed with mucilages, becaufe it is found

to

-EGGS. 415

to lie heavy on the ftomach, occafioning
naufea, and even vomiting.

I have found in animal matters, and par-
ticularly in the parenchyma of the liver,
dried in the air for feveral years, and in the
human mufcles altered by putrefaction, a
fubftance whieh poffeffes characters veryfimi-
lar to thofe of fpermaceti.

V. The eggs of birds, and particularly
thofe of poultry, are compofed, 1. Of a
bony {hell, which contains a jelly, and cal-
careous phofphat, as M. Berniard has proved.
2. Of a membranous pellicle, placed beneath
the fhell, and which appears to be an ex-
panfion of fibrous matter. 3. Of a whitifh
fluid fubftance. 4. Of a yellow fubftance
contained and fufpended in the middle of
the white ; the germ is fupported on this laft
fubftance.

White of egg is abfolutely of the fame
nature as the ferum of blood ; it is vifcid
and adhefive, it converts the fyrup of violets
to a green, and contains cretaceous foda in
a difengaged ftate ; expofed to a gentle heat
it coagulates into a white opake mafs, which
emits an hepatic fmell and gas. The white
of egg coagulated and dried in a water- bath,
affords an infipid phlegm, which putrefies,
and itfelf becomes dry and of a reddifh tran-
fparency refembling horn ; by diftillation in
a retort, it affords ammoniacal chalk, and
empyreumatic oil -, its coal contains foda,

and

416 EGGS.

and a fmall quantity of calcareous phofphat.
M. Deyeux has likewife obtained a fmall
quantity of fulphur by fublimation.

White of egg expofed to the air in fine
itrise, dries without putrefying, and forms
a kind of tranfparent varnifh. It is diflblved
in water in all proportions ; acids coagulate
it, and if the coagulum diluted with water
be filtered, the fluid which pafles through
affords by evaporation a neutral fait, confut-
ing of the acid combined with foda : fpirit
of wine likewife'coagulates the white of egg;
lime-water precipitates calcareous phofphat,
and the mercurial nitre precipitates phof-
phat of mercury, which by drying affumes
a rofe colour.

The yolk of egg is for the mofl part com-
pofed of an albuminous fubftance, which is
mixed with a certain quantity of a mild oil,
fo that the mixture diflblves in water, and
forms a kind of animal emuliion ; if it be
expofed to heat, it becomes lefs folid than
the white ; when dried, it undergoes a
kind of foftening, that arifes from the dis-
engagement of its oil, which exudes from
its furface in this ftate ; the oil may be ob-
tained by preffure, and is found to be mild
and infipid, and of a tafte and fmell (lightly
empyreumatic. The yolk of egg, after the
oil has been thus extracted, affords the fame
produfts by diftillation as all other animal
matters. Acids and fpirit of wine coagulate

it;

ICTHVOCOLLA, 4.I7

it ; the mild oil it contains exhibits a
ftriking analogy between the eggs of animals
and the feeds of vegetables, fince thefe laft
likevvife contain an oil which is in the fame
manner united with mucilage, and reduced
to the emulfive ftate.

Eggs are of great ufe as food ; the differ-*
ent parts are ufed in pharmacy and in medi-
cine ; the calcined fhell is ufed as an abfor-
bent; the oil of egg is foftening, and is
externally ufed in burns, chaps, &c. ; yolk
of egg renders oil foluble in water, and
forms lohochs ; it is triturated with refins,
camphor, &c. The white of egg is fuccefs-
fully ufed in pharmacy and confectionary,
to clarify the juices of plants, wheys, fyrups,
and other fluids ; it is likewife applied on
paintings, which it preferves by forming a
tranfparent varnifh on their furface.

VI. Idlhyocolla, or fifh glue, is a fub-
fiance partly gelatinous, and partly lym-
phatic, which is prepared by rolling up the
membranes that form the air bladder of
the fturgeon, and feveral other fifties, and
is dried in the air, after it has been twifled
into the form of a fhort cord as we receive
it. This fubftance affords a vifcid jelly by
ebullition in water $ by maceration for a
certain time in that fluid, it may be un-
wrapped and extended into a kind of mem-
brane. It is never brittle like the glafs pro-
perly fo called, but bends by virtue of its

Vol. IV* D d fibrous

418 ICTHYOCOLLA.

fibrous elaftic texture. A kind of glue is
likewife prepared by boiling the fkin of the
ftomach and inteftines of fifties, but it has
not the fame properties as ifinglafs or fifh-
glue. Icthyocolla affords all the products
of other animal fubftances ; it may be ufed
in medicine as an emollient in diforders of the
throat, inteftines, &c. ; but many other ve-
getable fubftances which poflefs the fame
virtue, are commonly preferred. It is ufed
in the arts to clarify liquors, wine, cof-
fee, &c. ; it attracts and precipitates all the
foreign fubftances wrhich affect their tranf-
parency.

CHAP. XXIII.

Concerning the Product: of Oviparous Qua-
drupeds, Serpents, Infects, and Worms,
which are ufed in Medicine and the
Arts.

THE turtle, the frog, the lizard, and
the viper, are ufed in medicine, de-
coctions or foups being made with their flefli
and bones, to which peculiar virtues are at-
tributed. It fhould feem, in fact, that the
zoophagous animals, whofe humours are
more attenuated than moft quadrupeds; whofe

parts

VIPERS. 4l9

parts In general have a Stronger fmell, and
appear to contain more faline matter, fince
they afford a large quantity of volatile alkali,
when diftilled by a gentle heat, after tritu-
ration with oil of tartar ; 'it mould feem, I
fay, that thefe animals muft poffefs Stronger
and more numerous virtues. Many phy-
ficians, however, call their virtues in quef-
tion, and clafs them with other animals.
Notwithstanding this opinion, it is Still
cuftomary to adminifter decoftions or foups
of turtle and frogs in diforders attended
with languor* confumptions without appa-
rent caufe, or any State of weaknefs which
fucceeds acute fevers ; and it is often found
that good effedts follow. Thefe decodtions
appear to be more nourishing, lighter, and
at the fame time poffeffed of a certain adti-*
vity, fufficiently indicated by their ftrong
fmell and peculiar taSte. Green lizards have
been greatly recommended for fome years
paft, in diforders of the fkin, cancers, &c.
Vipers are confidered as the mod adlive ;
the ancients fpoke highly of their virtues
in diforders of the ikin, in thofe of the
breaft, and in chronical diforders, wherein
the lymph is vitiated. We cannot avoid
thinking that their decodtions muit throw
off the vicious matter through the pores
of the fkin, by virtue of their exalted fpi-
ritus reftor ; their powder, and their vo-
latile fait has nearly the fame virtues; they
D d z are

420 tANTHARIDES.

are ftill admin iftered in fubftance as food
in the fame diforders, and with fuccefs.

The chemical analyfis of thefe animals by
M. Thouvenel, afforded a jelly, more or lefs
light, confident, or vifcid, an acute bitter
and deliquefcent extra<ft, an albuminous
concreicible fubftance, an ammoniacal fait,
and an oily fubftance of a peculiar tafte and
fmell, fometimes folubie in fpirit of wine,
&c.

II. Cantharides, a remedy of fo great
importance by its corrofive and epifpaftic
quality, coniift, according to M. Thou-
venel, i. Of a parenchyma, whofe nature
he has not determined, and which amounts
to half the weight of thefe dried infects,
2. Of three drachms in the ounce, of a
reddiih, very bluer extractive fubftance,
which affords an acid by diftillation. 3.
Of twelve grains per ounce of a yellow and
wax-like matter, which produces the golden
yellow colour of the cantharides ; this fub-
ftance when diftilled, affords a very pene-
trating acid, and a concrete oil, refembling
wax ; wrater diifolves the extract:, the yel-
low oil, and even a fmall quantity of the
green oil ; but ether attacks only this laft,
and may be fuccefsfully employed to fepa-
rate it from the others. The virtue of the
cantharides depends on this kind of green
wax. To obtain the latter, at the fame time
with the extractive fubftance, and to form in

general

ANTS. 421

general a tincture well charged with thefe
infects, a mixture of equal parts of fpirit
of wine and water muft be ufed, this mixed
tincture being diftilled affords a fpirit of
wine with a flight odour of cantharides, and
the different fubftances, it held in folution,
are feparated, one after the Gther, in pro-
portion as the evaporation goes forward.

III. The acid of ants was obferved by
Tragus, Bauhine, and feveral other bota-
nifls. We obferve the flower of chicory to
become very red in an ant heap. Samuel
Fifher, Etmuller, and Hoffman, have fuc-
ceffively made experiments on this acid.
Margraaf carefully examined it, and found
that ants contain a peculiar acid, fat oil,
and an extract. Meffrs. Arvidfon and Oerne,
have made the mofl complete feries of expe-
riments on this acid. The acid of ants are
obtained more efpecia-lly from the red ant,
formica rufa, by diftilling them in a retort,
and by wafhing them in boiling water. This
acid, when rectified, and rather concentrated,
has a penetrating fmell, and is corrofive ; its
tafte is agreeable when greatly diluted with
water, and it has thence been propofed to
be ufed inflead of vinegar -, it quickly red-
dens all blue vegetable colours, is decom-
pofed by fire, which converts it into the
cretaceous acid, and by the vitriolic and ni-
trous acids which difengage the fame creta-
ceous acid : it deprives the dephlogifUcated
V <} $ muriatic

422 ANTS.

muriatic acid of the bafe of air, and is ftronger
than the vitriolic, boraxic, cretaceous, .ace-
tous, and fuming nitrous acids. It forms
a kind of ether with fpirit of wine ; the
neutral falts it constitutes with alkaline'bafes
have been examined by Meffrs. Arvidfon and
Oerne. The formicate of pot-afh has been
prepared by M. Thouvenel, by fpreading
linen impregnated with pot-afh on ant-hills
uncovered ; the ants running over the cloth
emitted their acids, and odorant principle of
the fame nature, which they exhaled in fo
great an abundance, as to faturate the fixed
alkali fpread on the cloth The lixivium of
thefe linens afforded, by evaporation, a neu-
tral fait cryftailized in flat parallelograms,
and prifmatic columns which were not deli-
quefcent.

Lime with this acid forms a cryftallizable
and foluble fait ; in a word, the modern
chemifts confider the acid of ants as a pe-
culiar acid, fui generis.

Spirit of wine, digefted on ants, extracts a
fmall quantity of effential oil, which with this
fluid, forms the fpirit of magnanimity of Hoff-
man. If thefe infects be boiled in water, and
afterwards preffed, a fat oil is afforded, a-
mounting to about thirteen drachms in the
pound , this oil is of a greenifh yellow, con-
geals at a much warmer temperature than oil
of olives, and greatly refembles wax. The
water of the decoction affords a reddifk
brown extract by evaporation, which has a fe-
tid,

MILLIPEDES. 423

t?d, acidulous, and cafeous fmell, with a bit-
ter, naufeous, and acid tafte. This extract is
feparated into two fubftances by the fucceffive
application of water and fpirit of wine : the
parenchyma of ants deprived of thefe differ-
ent fubftances amounts to three ounces two
drachms in the pound.

IV. The millipedes, acelli, porcelli, oni-
fci, &c. prefented certain peculiar circum-
fiances in their analyfis made by M. Thou-
venel. By diftillation on the water-bath
without addition, they afford an infipid and
alkaline phlegm, fometimes effervefcing with
acids, and converting the fyrup of violets to
a green : in this operation they loft five-
eighths of their weight. By treatment with
water and fpirit of wine, they afterwards
afforded two drachms of foluble matter, in
the ounce ; of which more than two-thirds
were extractive matter, and the refidue an
oily or extractive fubftance. Thefe two
matters were eafily feparated by ether,
which diffolves the latter without touch-
ing the extract; ; they differ from thofe
of cantharides and ants, in affording more
concrete volatile alkali, and no acid in their
diftillation. M. Thouvenel obferves, on this
fubject, that among infects the millipedes
appear to have the fame relation to cantha-
rides and ants, which reptiles have with
refpect to quadrupeds.

The neutral falts contained in thefe in-
fers are very fmall in quantity, and very
D d 4 difficult

424. MILLIPEDES.

difficult to be extracted. M. Thouvenel
affirms, that the millipedes and earth-worms,
lumbrici, conftantly afforded him marine
fait, with earthy bafts, and bafe of vegetable
alkali; while in ants, and cantharides, thefe
two bafes, the firft of which always appeared
to him the moft abundant, are united with
an acid, which has the character of the phof-
phoric acid. It is neceflary to be obferved
here, that this chemift in his DifTertation,
has not defcribed either the methods of ex-
trading thefe falts, nor the proceffes he made
ufe of to afcertain their nature.

Cantharides and millipedes are only ufed
in medicine; the latter appear to aft as
ftimulants, and flight diuretics, and for
this purpofe they ought to be administered
according to the experiments of M. Thou-
venel, in a much more confiderable dofe than
is ufually prefcribed. The expreffed fluid
of forty or fifty living millipedes given in a
mild drink, or mixed with the juice of cer-
tain aperient plants, may be fuccefsfully
prefcribed in the jaundice, ferous diforders,
coagulations of the milk, &c. As to the
cantharides, it is one of the moft powerful
medicines we ape in poffeffion of. M. Thou-
venel tried on himfelf the effeft of the green
waxy matter, in which the virtue of thefe
infefts refides \ when applied on the fkin in
the quantity of nine grains, it raifed a blifter
full of ferous matter, in the fame manner as

the

HONEY, WAX. 425

the powder of cantharides ; but the mod: va-
luable obfervations refulting from his expe-
riments on this powerful remedy, relate to
the fpirituous tincture of cantharides. He
ufed it with the greateft fuccefs externally,
in a dofe of two drachms to two ounces and
an half, in rheumatic and fciatic pains, and
in the wandering gout ; it heats the parts,
accelerates the circulation, and excites eva-
cuation by fweat, urine, and flool, according
to the parts on which it is applied. He
likewife relates certain good effects arifing
from this tincture internally adminiftered by
foreign phylicians, but young practitioners
ought to be advifed that the internal ufe of
this medicine fhould be very moderate, as it
has been known to produce flufhings on the
fkin, inflammations, fweating of blood, and
pains in the loins and bladder, dyfente-
ries, &c.

V. Honey and wax, prepared by bees,
feem to belong to the vegetable kingdom,
fince thefe infects collect the firft in the
nectaria of the flowers, and the fecond in the
anthers of their ftamina ; neverthelefs they
have paffed a peculiar elaboration, and be-
fides, as they are obtained in confequence of
the labour of bees, their properties ought to
be examined in the hiflory of infects.

Honey is a fubftance perfectly refembling
faccharine juices, which we have treated of
under vegetables. It has a white or yellow-

i£h

426 WAX.

ifh colour, a foft and grained confidence, a
faccharine and aromatic fmell ; by means of
fpirit of wine, and even by water, with pe-
culiar management, a true fugar is obtained;
by diftillation it affords an acid phlegm and
an oil, and its coal is light and fpongy like
that of the mucilages of plants. The ni-
trous acid extracts an acid intirely fimilar to
that of fugar ; it is very foluble in water,
with which it forms a fyrup, and like fu-
gar, paries to the fpiritous fermentation ; it
is an excellent food, and a foftening, and
llightly aperient medicine ; it is given dif-
folved in water, and mixed with vinegar,
under the name of oximel. It is often com-
bined with different acrid plants, as in the
oxymel of fquills, of colchicus ; it is the
vehicle in many medicines which bear its
name, as the honey of rofes, water-lilly,
mercurial honey, &c.

Wax is a concrete oily fubftance, fimilar to
folid fat oil, fuch as the butter of cocoa, and
ftill more refembling vegetable wax. Though
it cannot be doubted that this fubftance is
extracted from the ftamina of flowers, it is
neverthelefs certain, that it receives a pecu-
liar elaboration in the body of the animal";
fince, according to the trials of Reaumur,
a flexible wax cannot be made with the
powder of the antherae. Wax which com-
pofes the honey-combs is yellow, and of an
infipid tafte; it is whitened by expofure to

the

WAX. 427

the action of dew, and of the air. After it
has been reduced into thin pieces, the aerated
muriatic acid whitens it very quickly ; by a
gentle heat it foftens, melts, and forms a
tranfparent oily fluid, which becomes folid
and opake by cooling ; when ftrongly heated
with the contact of air, it takes fire as foon
as it is volatilized ; and this is the effect pro-
duced by the wick in candles. When dif-
tilled in a retort it affords an acid phlegm,
of a ftrong and penetrating fmell j an oil
at firft fluid, which afterwards fixes in the
receiver, and has the confidence of butter j
and leaves only a very fmall quantity of coal
difficult to incinerate. Butter of wax being
rectified a number of times, becomes fluid
and volatile ; wax does not alter by expo-
fure to the air, except that it becomes co-
loured at the end of a certain time. It dif-
folves in oil, to which it gives confidence ;
when melted in thefe fluids in a mild heat,
it forms medicaments, known by the name
of cerates ; fpirit of wine does not act on wax ;
acids blacken it, alkalis combine with it,
and convert it into foap.

Wax is ufed in a great number of arts ;
in pharmacy it is ufed in the preparations
of pomatums, unguents, and planners.

VI. Silk worms contain, efpecially when
in the ftate of chryfalis, an acid liquor in
the refervoir placed near the anus. M.
Chauflier, of the Academy of Dijon, ob-
tained

428 SILK.

tained this acid by exprcffing the juice of
€he chryfalides in a cloth, and precipitating
the mucilage by fpirit of wine, and like-
wife by infufing the chryfalides in that li-
quor. This acid is very penetrating, of a
yellow amber colour, but its nature and
combinations are not yet known.

Many other infects likewife contain acids ;
the large caterpillar of the willow emits a li-
quor confiderably acid, according to the re-
mark of M. Bonnet. I have often obferved
the buprefles and ftaphylini give a red colour
to the blue paper with which boxes were
lined, wherein they were put. M. Chauffier
has likewife obtained an acid from the grafs-
hopper, the red bug, the lampyris, or min-
ing worm.

Silk, which feems to be nothing but
a kind of gummy matter dried, differs
neverthelefs from vegetable fubftances, 1.
By the volatile alkali it affords in diftillation*
2. By the mephitis obtained from it, by
means of the nitrous acid. 3. By the pecu-
liar oil which this acid feparates in propor-
tion as it converts it into faccharine acid, as
M. Berthollet has fhewn. It feems to be a
compound of vegetable mucilage with a pe-
culiar animal oil, which gives it flexibility,
ductility, and elafticity.

VII. The improper name of gum lac is
given to a refinous fubftance of a deep red,
which is depofited on the branches of trees,

by

KERMES. 429

by a kind of ant peculiar to the Eaft-Indies.
This fubftance appeared to Geoffroy to be
a kind of nidus, in which the ants depofit
their eggs. In fadt, if ftick-lac be broken,
it is obferved to be full of fmall cavities, or
regular cellules, in which fmall oblong bo-
dies are placed, which Geoffroy has confi-
dered as the embryoes of ants. He thinks that
the lac owes its colour to this animal fub-
ftance; he regards the lac as a true wax,
though its drynefs, the aromatic odour it
exhales in burning, and its folubility in fpi-
rit of wine, feem to indicate a refemblance
between it and refins ; by diftillation it af-
fords a kind of butter, according to the fame
author. It is diftinguifhed in commerce
into ftick-lac, feed-lac, and fhell-lac. It is
ufed in the Levant to dye cloths and fkins.
It is the bafis of fealing wax -y a tindture is
made with it, together with the fpirit of
cochlearia ; it enters into the troches of am-
ber, dentrifrice powders, and opiates, odo-
rous paftills, &c.

VIII. Kermes, Cocus infedtorius, was
confidered by the firft naturalifts as a tuber-
cle and excrefcent of plants. The more ac-
curate obfervations of fubfequent times have
(hewn, that it is the female of an infedt ar-
ranged among hemiptera by Geoffroy ; this
female fixes itfelf among the leaves of the
holm, where, after having been fecundated,
it extends itfelf, dies, and foon lofes the form

of

430 CtiCHINEAL.

of an infect; it has the appearance of a
brown red cap, under which are inclofed a
very great number of eggs. This cap was for-
merly ufed in dying, but has been neglected
iince the difcovery of cochineal. Kermes
exhibits the fame chemical properties as this
laft fubftance; it enters into the confectio
alkermes.

IX. Cochineal, like kermes, was long
confidered as a vegetable grain. Father Plu<-
mier is among the firft who detected this
error ; it is, in fact, the female of an infect
which differs from the kermes in the circtim-
fiance that it preferves its form, though fixed
on the plants. The cochineal ufed in dye-
ing grows on the opuntia or Indian fig;
it is collected in great quantities in South
America. Geoffroy, who analyzed it, found
it to contain the fame principles as ker-
mes ; he obtained the volatile alkali from it.
The form of this infect may be feen by ma-
cerating it in water. Cochineal is ufed to
make carmine, and in dying it produces ei-
ther a crimfon or fear let colour, according
to the manner in which it is ufed. As it is
an extractive colouring matter, it cannot be
applied in fubftances intended to be dyed,
but by the help of a corrofive. It readily
adheres to wool, and tinges it of a fcarlet
colour, by means of the folution of tin in
aqua regia, which decompofeb the colouring
extract, and fingularly enlivens the tinge.

The

CRABS EYES. 43 1

The method of giving this beautiful colour
to filk was not known before the time of
Macquer ; this celebrated chemift difcovered
that filk may be dyed, if previoufly impreg-
nated with the folution of tin, before it is
plunged in the bath of cochineal, inftead of
mixing the folution in the bath, as is done
with wool.

X. The ftrong concretions falfely called
crabs eyes, lapides cancrcrum, are found
in the number of two in the internal and
interior parts of the flomach of thefe in-
fers ; they are round, convex on one fide,
concave on the other, and placed in the ani-
mal between the two membranes of the ven-
tricle. As they are not found, but at the
time in which the crabs change their cover-
ing and their ftomach; and as they difappear
gradually in proportion as the new covering
becomes hard, it is thought, with great
probability, that they ferve to re-produce
the calcareous fubftance, which conflitutes
the bafis of their fhells.

Thefe ftones have no tafte ; they contain
a fmall quantity of gelatinous matter -y they
are prepared by repeated wafhing and grind-
ing on a ftone with a fmall quantity of water
to reduce them into a foft parte, which is
moulded into lozenges and dried ; the wrater
carrying off the animal jelly contained in
thefe ftones ; the refidue is mere earthy mat-
ter. When prepared in this manner, they

make

432 CORAL.

make a ftrong effervefcence with all acids,
and are abfolutely of the fame nature as
chalk ; they have, therefore, no other vir-
tue than that of abforbing acidities in the
firft paffages ; and the opinions in confe-
quence of which animal fubftances in gene-
ral have been placed in the rank of aperient,
diuretic, and even cordial remedies, are very
far from being well founded.

XI. The fame obfervation likewife applies
to coral, which is a calcareous white earth,
or rofe-coloured ramification, forming the
bafis of the habitation of the fea polypi.
Preparations of thefe are made in the fame
manner as from crabs eyes, and it is of the
fame calcareous nature as that fubftance ; it
enters into the confedlio alkermes, pulvis
gutteti, amber troches, &c. Numberlefs
virtues have been attributed to it, but it
pofTeffes no other than that of a mere ab-
sorbent, unlefs it be combined with acids ;
this, as well as crabs eyes, is often in the
ftate of a neutral fait, combined with vine-
gar or lemon juice, as an afperient diure-
tic, &c.

XII. The coralline, called fea-mofs, is,
as we have obferved, a peculiar habita-
tion of polypi. It affords the fame princi-
ples in the retort as animal fubftances, and
has a fait, bitter, and difagreeable tafte ; it
is fuccefsfully ufed as a vermifuge, with
which intention it is prefcribed in powder,

in

PUTREFACTION. 433

in the dofe of twenty-four grains for infants,
to that of two drachms or more for adults.
It is made into an anthelminthic fyrup, and
enters into vermifuge powders. This com-
mon coralline muft not be confounded with
the fubftance at prefent called coralline of
Corfica, or helminto-corton : this laft is a
vegetable, a kind of fucus, which has the
property of forming a jelly with hot water.

CHAP. XXIV.

Concerning the Putrefaction of Animal Sub-
fiances.

/~psHOUGH vegetable fubftances are fuf-
•** ceptible of decompofition, and intire
deftruction, by the putrid fermentation, they
are neverthelefs in general far from being as
capable of entering into this ftate of inteftine
motion as animal matters ; the putrefaction
of thefe laft is much more rapid and its phe-
nomena are different : all the fluids and foft
parts of animals are alike capable of under-
going this procefs, while many vegetable mat-
ters feem exempted from it, or at leaft are not
changed by it but flowly, and with great dif-
ficulty.

The putrefaction of animals, which we

cannot but conlider, with Boerhaave, as a

Vol. IV", E e true

434

PUTREFACTION,

true fermentation, is one of the mod impor-
tant, and at the iame time the moft difficult
to be known ; all the labours of the philo-
fophical world, iince the time of Lord Chan-
cellor Bacon, who was well aware of the
importance of inquiries into this fubject,
have ferved only to clear up a few circum-
ftances, and to exhibit the general pheno-
mena of putrefying fubflances. Beccher*
Hales, Stahl, Pringle, Macbride, Geber,
Baume, the valuable author of the Effays
on Putrefaction, and thofe of the Difierta-
tions on Analeptics, which were crowned
in 1767 by the Academy of Dijon, have ob-
ierved, and carefully defcribed the facts
which accompany the putrid change in bo-
dies : but we fhall fee, in the following
pages, that a great number of experiments
remains to be made, before we can efteem
ourfelves acquainted with the whole of the
phenomena of this natural operation.

Every fluid or loft animal fubftance, ex-
pofed to a moderate temperature, of fixty-five
degrees or more, pafles with more orlefs ra-
pidity through the following changes. Its
colour becomes paler, and its confidence
diminifhes; if it be a folid part, fuch as
flefli, it lbftens, and a ferous matter fweats
out, whofe colcur quickly changes ; its tex-
ture becomes relaxed, and its organization
deftroyed; its fmell becomes faint, and dif-
agreeable j the fubftance gradually finks

down,

PUTREFACTION. 435

down, and is diminifhed in bulk ; its fmell
becomes ftronger, and alkaline. If the fub-
jed: be contained in a clofe vefTel, the pro-
grefs of putrefaction, at this ftage, feems to
flacken ; no other fmell but that of a pun-
gent alkali is perceived ; the matter effer-
vefces with acids, and converts fyrup of
violets to a green. But if the communica-
tion with the air be admitted, the urinous
exhalation is diffipated, and a peculiar putrid
fmell is fpread around, with a kind of impetuo^
fity; — a fmell of the moft infupportablekind,
which lafts a long time, and pervades every
place, affecting the bodies of living animals,
after the manner of a ferment, capable of
altering the fluids : this fmell is corrected,
and as it were confined by the volatile alkali.
When the latter is volatilized, the putre-
factive procefs becomes active a fecond time,
and the fubftance fuddenly fwells up, be-
comes filled with bubbles of air, and foon
after fubfides again. Its colour changes, the
fibrous texture of the flefh being then fcarce-
ly diftinguifhable ; and the whole is changed
into a foft, brown, or greenifh matter, of
the confiftence of a poultice, whofe fmell is
faint, naufeous, and very active on the bo-
dies of animals. The odorant principle gra-
dually lofes its force ; the fluid portion of
the flefh afTumes a kind of confiftence, its
colour becomes deeper, and it is finally re-
Ee 2 duced

436 PUTREFACTION.

duced into a friable matter, rather deliquef-
cent, which being rubbed between the fin-
gers, breaks into a coarfe powder, like earth.
This is the laft ftate obferved in the putre-
faction of animal fubftances ; they do not
arrive at this term but at the end of a con-
fiderable time. Eighteen months, two, and
even three years, are fcarcely fufficient for
the deftruftion of the whole body of animals
expofed to the air ; and the time neceffary
for the total deftruction of bodies buried in
the earth has not yet been eftimated. Not
to mention bodies which in certain foils are
dried, and remain unchangeable ; many facts
prove, that human bodies, buried in great
numbers in a moift foil, are not deftroyed
even at the end of thirty years.

From this outline it follows, 1. That the
conditions proper to develope and maintain
the putrefaction of animal fubftances, are
the contact of air, heat, moifture, and re-
pofe. 2. That the volatile alkali is the pro-
duct of putrefaction, formed during that
procefs, fince it did not exift as fuch in the
animal fubftances before the commencement
of that inteftine motion. 3. That putre-
faction, effected by the inteftine motion, pro-
per to organized matters, may be compared
to the action of fire, as Mr. Goddard has re-
marked, and may be ccnfidered as fpontaneous
decompofition, as M, Baume thinks, from

which

PUTREFACTION. 437

which it differs only in its flownefs. 4. That
in this natural operation, the proximate prin-
ciples of animals re-act on each other, by
the affiltance of water and of heat, by means
of which the motion commenced ; that the
volatile matters thus formed, become gra-
dually diffipated in the order of their vola-
tility, and that nothing remains after the
putrefaction, but an iniipid, and as it were
earthy fubftance. 5, and laftly, That the
putrid exhalation, which is fo well diftin-
guifhed by the nerves of fmell, and whofe
action is fo powerful on the animal eco^
nomy, may be considered as one of the
principal products of putrefaction, as it is
peculiar to this operation, and is not obferv-
ed in any other natural phenomena ; and be-
caufe it appears capable of developing the
putrefactive motion in all the animal fub-
ftances which are expofed to its action. As
to the nature of this fugacious odorant fub-
ftance, we mud: obferve, that it is more par-
ticularly with refpect to this that inquiries
are very little advanced, though they highly
deferve tq be followed. We only know, that
it is extremely volatile, attenuated, and pe-
netrating ; that pure air, water in large quan-
tities, and acid gafes, are capable of mode-
rating its effects. Though it ought not to be
confounded with the cretaceous acid, or fixed
air, which is difengaged in large quantities
E e 3 from

438 PUTREFACTION.

from putrefying bodies, and to whofe dis-
engagement Macbride intirely attributed the
caule of this natural phenomenon ; and
though we are by no means warranted in
comparing it, either to the inflammable gas
difengaged from putrefcent bodies, nor with
the luminous matter, which mines at the
furface of putrid animal fibres, converting
them into a kind of phofphorus ; yet it muft
be allowed, that thefe fubflances have very
evident relations with each other, fince it
always accompanies them, is equally vola-
tile and attenuating, and acts with equal
energy on the organs of animals. Four de-
grees or ftages of the putrid of fermentation
may be diftinguifhed, according to M. Boiflieu.

The firft, which this phyfician calls a ten-
dency to putrefaction, confifts in an altera-
tion, not coniiderable, which appears by a
faint or flight fmell, and a foftening of the
fubftance.

The fecond degree, or commencement of
putrefaction, is fometimes indicated by marks
of acidity : the fubftances which undergo
this, lofe weight, become fetid and foft, and
a ferous matter exudes, if they be in clofe
vefTels -y or they become dry, and of a dark
colour, if expofed to the air.

In the third degree, or advanced ftage of
putrefaction, the putrefcent matters emit an
alkaline fmell, mixed with the putrid and

naufeous

PUTREFACTION. 439

naufeous fmell ; they fall into diflblution,
their colour changes more and more, and
they lofe at the fame time both weight and
bulk.

Laftly, the fourth degree, or that of com-
plete putrefaction, is known by the volatile
alkali being intirely and completely diflipat-
ed; the fetid fmell lofes its force, the vo-
lume and weight of the putrefied fubflance
are confiderably diminifhed, a gelatinous
mucus is feparated, they dry by degrees,
and are at length reduced to a friable and
earthy matter.

Such are the general phenomena obferved
in the putrefaction of animal fubftances, but
they are far from being the fame in all mat-
ters which putrefy. There is a great diffe-
rence between the putrefaction of the parts of
living animals, and that of their dead. organs.
The motion which exifts in the former, An-
gularly modifies the phenomena of this altera-
tion; and phyficians have frequent opportuni-
ties of observing the difference between thefe
two ftates, with refpect to putrefaction. Be-
fides this, every humour, and every folid
part, feparated from a dead animal, has like-
wife its peculiar manner of putrefying. The
mufcular, membranous, or parenchymatous
texture of the organs ; the oily, mucilagi-
lous, or lymphatic nature of the humours,
their confiftence, their ftate with refpeft to
E e 4 that

44° PUTREFACTION.

that of the animal which afforded them,
greatly influence the putrefactive motion,
and modify it in a thoufand manners, per-
haps impoffible to be eftimated. And ho\v
greatly will the difficulty of the fubject be
increafed, if we add to this enumeration,,
the ftate of the air, its temperature, elafti-
city, weight, drynefs, or moifture ; the ex-
position of the putrefying fubftance in va-
rious places, and even the form of the veffels
which contain it y all thefe circumftances
being capable of varying the phenomena ?
It muft therefore be allowed, that thexhif-
tory of animal putrefaction is fcarcely be-
gun, and that it demands an immenfe feries
of inquiries and experiments.

The phenomena hitherto obferved mew,
that water is the caufe of putrefaction ; it is
moft probable that this fluid is decompofed,
that its oxyginous principle feizes the mephi-
tis of the animal fubftances, and contributes to
the formation of the nitrous acid, fo frequent-
ly found in animal matters j and that the in-
flammable gas of the water,' united to a porr
tion of the fame mephitis, which abounds
in thefe fubftances, produces the volatile al-
kali that flies off. The oily principle is
preferved for the longeft time ; the calcare-
ous phofphat, and the phofphat of foda,
united to a portion of the carbonaceous
principle, and perhaps with a fmall quan7

tity

PUTREFACTION. 441

tity of the fat matter, feem to conftitute the
apparently earthy refidue of putrefied animal
matters.

Thefe general data are fufficient to {hew,
that putrefa&ion feparates and volatilizes the
principles of animal matters j that nature
reduces them, by the flow decompoiition of
dead animals, to the moft Ample fubftances,
deftined to enter into new combinations;
and that it is in this manner that the pur-
pofes of the general fyftem are accomplifhed,
by the continual change of the form and na-
ture of bodies, which pafs without inter-
miflion from one kingdom to another.

The END,

( 443 )

INDEX.

Note, The Numerical References to the
Pages, belong to the Volume whofe Num-
ber has been immediately before denoted
by Roman Capitals. If no fuch Letters
precede, the firft Volume is meant.

A CACIA, Juice of, IV. 18.

•^■^ Achromatic Lenfes, III. 202.

Acids, lxxii. vegetable lxxxii. et feq. II. i0

Acid, acetous, IV. 201. et feq.

Acid of ants, IV. 421.

Acid arfenical, II. 446. et feq.

Acid of borax, II. 51 — 56.

Acid cretaceous, II. 3 — 12. IV. 124.

Acid fermentation, IV. 197 — 217.

Acid galaftic, IV. 304.

Acid lithiafic, IV. 366.

Acid marine, II. 13. dephlogifticated, 18.
procefs for obtaining, 102.

Acid of molybdena, II. 263. et feq.

Acid, nitrous, II. 25 — 40. fee alfo nitre. — -
purified, III. 342. detonates with char-
coal, IV. 126.

Acidum perlatum, IV. 362.

Acid, phofphoric, found in lead ore, III.
193. General account of, IV. 383 — 39 1*

Acid,

444 INDEX.

Acid, febaceous, IV. 321.

Acid of filk-worms, IV. 428.

Acid, fparry, II. 20 — 25.

Acid of fugar, IV. 34—40.

Acid of fugar of milk, IV. 308*

Acid of tartar, IV. 193.

Acid of tungften, II. 271.

Acid, ^vitriolic, II. 41 — 50. Preparation

of, 380.
Adhefion, Morveau's experiments on, 86.
iEthiops mineral, III. 150. Martial, 226*

273-
iEtites, III. 219.

Affinities, chemical, 42. et feq. Double,
76. Tables of, by Geoffroy, 80. By
Bergman, 81.

Aggregation, 45.

Air, atmofpheric, xxxvii. et feq. 164, et
feq. Its purity afcertained by nitrous
gas, II. 33.

Air, nitrous, fee gas, nitrous.

Air, vital, xxxiii. et feq.

Alchemy, 30.

Algaroth, powder of, III. 140.

Alkali, lxxi. 382. Vegetable, 383. IV. 179.
Mineral, 387. Volatile, 389. See cre-
taceous tartar, fal-ammoniac cretaceous,
and cretaceous foda.

Alkanet, IV. 113.

Alloy, fufible with the heat of boiling wa-
ter, III. 212.

Aloes, IV. 85.

Alum,

iNBSX. 445

Alum, II. 229 — 246.

Amalgam, III. 180. 211. 321. 353.

Amber, III. 413. — 424.

Ambergris, III. 434 — 438.

Ammoniacal vitriol, II. 132. nitre, 134.

phofphat, IV. 355, et feq.
Analyfis, 3 — 5. of animal fubftances, IV.

279 — 288.
Anatomy of Fifths, IV. 244. of infe&s, 247,
Animals, IV. 222, et feq.
Annatto, IV. iii.

Antimoniated or emetic tartar, IV. 190.
Antimony, III. 32 — 67. Butter of, 138.
Aptera, IV. 255.
Aqua regia, II. 28.
Arabians, chemiftry of, 29.
Arabic, gum, IV. 44.
Arbor Dianae, III. 344.
Archil, IV. 112.
Ardent fpirit, IV. 148. Requires to afcer-

tain its purity, 151.
Arfenic, II. 435 — 451. Butter of, III. 137,
Affafcetida, IV. 84.

AfTay of filver, III. 333. of gold, 378.
Afphaltos, III. 424 — 427.
Aftringent matters, and iron, III, 250.
Aurum fulrninans, III. 366.

B

Balfams, IV. 74. of Mecca and Copaiba, yy.
Bark, IV. 3.

Barytical

446 INDEX.

Barytical vitriol, II. 250. fluor, 260. chalk,
260. ,

Beccher, 211.

Beer, IV. 143,

Ben, oil of, IV. 56.

Benzoin, IV. 74.

Bergman, 43. His chemical diftribution of
earths and ftones, 313—331.

Berthollet, xxxix. On the nature of animal
fub fiances, iv. 283.

Bile, IV. 325, et feq.

Biliary concretions, IV, 330.

Birds, IV. 262.

Bifmuth, III. 1 — 11. Butter of, 138.

Bitumens, III. 408 — 413.

Blende, III. 75.

Blood, IV. 288—300.

Blow-pipe, 237.

Blue, Berlin or Pruffian, III. 252.

Bodies, dead, remain long in the earth be-
fore they are totally deftroyed, IV. 436,

Boerhaave, his procefs for making vinegar,
IV. 198.

Bolognian phofphorus, II. 253.

Bones, IV. 400 — 406.

Borax, II. 108 — 116. Vegetable, 116. Cal-
careous, 172. Magnefian, 218. Ar-
gillaceous, 247. Barytic, 258.

Boyle, 167.

Brain, IV. 276.

Branchiae, IV. 26 3*

Brandy, IV. 146*

Brafs,

index, 447

Brafs, III. 321.

Briflbn, IV. 232.

Bronze, 325.

Bryony, IV. 94.

Bucquet, his chemical divifion of earths

and ftones, 268 — 312.
Burgundy pitch, IV. 79.
Butter, IV. 313.
Butter of arfenic, III. 137. of bifmuth,

j 38. of antimony, 138.

Cachou, IV. 21.

Calcination, 154., Theories of, II. 4^2—

426.
Calculi in the gall-bladder, IV. 330.
Calculi in the urinary bladder, IV. 365.
Calx, metallic, II. 420.
Camphor, IV. 61 — 66.
Cantharides, IV. 420.
Caout-chouc, IV. 87.
Carthamus, IV. 112.
Caffava, IV. 95.

Caffius, purple powder of, III. 370.
Caftoreum, IV. 409.
Cavendifh, Mr. xl. compofes nitrous acid,

11. 38.

Cendres gravelees, IV. 147.

Cetacea, IV. 233. 276.

Chalk, II. 179 — 201. Argillaceous, 248.

Chalybeated tartar, IV. 194,

Char-

448 INDEX.

Charcoal, or vegetable coal, IV. 122.
Chemiftry defined, 1 . Its various ufes, 9—

24. Its rife and progrefs, 25,. et feq.
Cheefe, IV. 311.
Chio turpentine, IV, jf.
Choak-damp, III. 429.
Chryfocolla, green and blue, III. 296, 297*
Cimento, the academy del, 191.
Cinnabar, III. 105, et feq, 151.
Circulation, IV. 259.
Clay, 217, et feq.
Coal, pit, III. 428-— 432^
Coak, III. 431.
Cobalt, II. 451 — 461.
Cochineal, IV. 430.
Cocoa, butter of, IV. 56.
Coleoptera, IV. 254.
Combuftion, lxvi. 174. II. 325 — 332,

flow, of phofphorus, IV. 384.
Colour, 106. IV. 106, et feq.
Compolition, 5 — 7. Affinity of, 53, et

feq.
Congelation of mertury, III. 95—- 97.
Concentration, 160.
Copper, III. 294 — 325.
Coral, IV. 432.
Coralline, IV. 432*
Corrofive fublimate, III. 131, et feq.
Corrofives, IV. 109.
Cow's milk, IV. 301.
Crab's eyes-, IV. 431.
Cream of tartar, IV, 181.

Cretan

index. 449

Cretaceous tartar, II. 119 — 127.
Cretaceous foda, II. 127— 131.
Cretaceous fpar, fee Chalk.
Cronftedt, 214.
Crucibles of platina, III. 400.
Cupellation, 155. III. 333.
Cyder, IV. 142.

Daubenton, his lithologic method, 239 —
266. Divifion of oviparous quadru-
peds, IV, 239.

Deco&ion, 16 1.

Decompofition, 3 — 5.

Detonation, 156. of mercurial precipitates,
III. 129.

Diamond, lxiii. II. 332 — 344.

Diaphoretic antimony, III. 46.

Diefbach, inventor of Pruffian blue, lit. 253.

Digeftion, 160. IV. 264.

Diptera, IV. 255.

Diftillation, 158. deftru&ive, IV. 114.

Dragon's blood, IV". 82.

Dudtility, II. 402. of gold, III. 3560

Dundonnald, Lord, III. 432.

Dying, the art of, IV. 107 — 114.

Earth in general, 210. vitrefiable, 217. ar-
gillaceous, 217, et feq. the method
of analyzing them, 346.
Vol. IV. F f EbuU

45° INDEX.

Ebullition, 192.

Efflorefcence, II. 69.

Eggs, IV. 415.

Egyptians, their chemiftry, 26*

Elaftic fluids, fee Gas.

Ele&ricity, III. 350.

Embalming, III. 426.

Emery, III. 221.

Entomology, IV. 246*

Epfom fait, II. 205.

EiTay, fee AfTay.

Effential oils, IV. 58 — 61.

Effential falts, IV. 23.

Ether, IV. 157. vitriolic, 158. nitrous,

163. marine, 169. acetous, 214.
Euphorbium, IV. 84.
Evaporation, 157.
Excrements, IV. 341.
Extracts, IV. 22.

F.

Fat, IV. 316—325.

Fat oils, IV. 48, 55.

Fecula, IV. 92.

Fermentation, xciii. IV. 136, et feq.

Fibrous part of the blood, IV. 297. of muf-

cular flefh, 399.
Fire, 98, et feq. 149.
Fifhes, IV. 241.
Fixed air, fee Gas, Cretaceous Acid.

Fixity,

INDEX* 451

Fixity, 145, et feq.

Fufible fait of urine, IV. 354,

Flour, IV. 98.

Flowers, IV. 4.

Fluor fpar, II. 173.

Form or figure confidered as a character of
minerals, 227.

Fracture, 232.

Freezing of water by ether, IV. 161.

Fruits, IV. 5.

Fulminating gold, III. 366.

Fulminating powder, II. 387.

Functions of vegetables, IV. 2. 7. of ani-
mals, 258.

Fufion, 155.

G.

Galbanum, IV. 83.

Galena, III. 196.

Galipot, IV. 80.

Gall, IV. 325.

Gas, xxii, et feq. xxviii. Claflification of,

xxxii. General fadts in which they are

concerned, lxiv.
Gas, aerated muriatic* or dephlogifticated

marine, xliii. II. 18.
Gas, alkaline, lii. 390.
Gas, cretaceous acid ; or fixed air, xlvi. II.

3, et feq.
Gas, cretaceous, inflammable, lx.
Gas, fluor, or fparry acid, 1. II. 21.

F f 2 Gas,

4J2 INCEX.

Gas, hepatic, lvi. II. 368. 371 — 376.

Gas, mephitized inflammable, or inflam-
mable air of marfhes, lix.

Gas, muriatic acid, li. II. 13.

Gas, nitrous, xli. et feq. II. 32, 33.

Gas, phofphoric, Iviii. IV. 379.

Gas, fulphureous, condenfed by cold, xxxi—
xlix. Its properties, II. 46.

Gas, pure or aqueous inflammable, liii. II.

344—354-
Gaftnc juice, IV. 334—337.

Generation of vegetables, IV. 14, Of ani-
mals, 269.

Geoffroy, IV. 252.

Glafs tube, blackened by inflammable gas,
III. 210.

Glafs of phofphorus, IV. 385.

Glauber's fait, II. 67 — 71.

Glue, IV. 392.

Glutinous part of wheat, IV. 99. of ani-
mals, 299.

Gold in leaf is tranfparent, II. 401. Other
properties, III. 355—383.

Gouan, M. his icthyologic fyftem, IV. 245.

Goulard's extrad: of Saturn, IV. 208.

Greeks, chemiiiry of, 26.

Guiacum, gum, IV. 81 •

Gum, IV. 43.

Gum-ammoniac, IV. 86.

Gum, elaftic, IV. 87.

Gum-elemi, IV. 80.

Gum guttae, IV. 84.

Gum-

INDEX, 45$

Gum-lac, IV. 428.
Gum-refins, IV. 18 — 82.
Gunpowder, II. 382 — 386.
Gypfum. See Vitriol of Lime.

Hales, xlii.

Halle, M. his obfervations on the fponta-

neous changes of urine, IV. 350.
Hardnefs, a character of ftones, 228.
Hartfhorn, IV. 411. Spirit, fait, and oil

of, 412.
Heat, xxiv. et feq. Ixv. et feq. 108. et

feq. 142. et feq. 151.
Hellot firft mentioned the fait of urine, IV.

358. His defcription of the method of

making phofphorus, 371.
Hematites, III. , 220.
Hemiptera, IV. 254.
Hempfeed oil, IV. 56.
Hepar, II. 364.

Hepatic ore of copper, III. 296.
Hermftadt, his experiments on milk, IV,

310.
Hoffman's whey, IV. 301.
Honey, IV. 425.
Human fat, IV. 319.
Hymenoptera, IV. 255.
Hypociftis, IV. 19.

F f 3 Japan

454 INDEX.

I. J-

Japan earth, IV. 23.

Ice, 187.

Icthyocolla, IV. 417.

Icthyology, IV. 241.

Jelly, IV. 393.

Jet, III. 427-

Indigo, IV. 113.

Inflammation of iron and fulphur, III. 285,

Infufion, 161.

Ingenhoufz on vegetables, IV. u. 71.

Ink, III. 251.

Infects found in amber, III. 414. IV. 247.

Iron, xlvii. III. 216---294. In plants, IVW

134. In blood, 297.
Irritability, IV. 272.
Ifinglafs, IV. 417.
Juices of plants, IV. 16.

K.

Kermes, mineral, III. 45. the infedt, IV. 429.

Keyfer's pills, IV. 216.

Kirwan, Mr. his clarification of earths and

ftones, 331— 345.
Klein, IV. 230 — 235.

L-

Labdanum, IV. 81.
Lac virginale, IV. 75.
Lamp-black, IV. 123.
Lapis calaminaris, III. 69.
Lapis infernalis, III. 340,

Lavoi£er#

INDEX. 455

Lavoifier, M. xxix. et paffim. His cele-
brated experiment of decompofing the
nitrous fait of mercury, II. 36.

Lead, III. 188 — 216.

Leaves of vegetables, IV. 3.

Light, xxiv. et feq. Difengages the oxy-
ginous principle, xxxvii. Its general
effects on bodies, Ixviii. 100, et feq.

Lime, 375. II. 201.

Linnaeus, his divifion of the mammalia, IV.
228. Of birds, 235. Of amphibia, 237.

Liquorice, IV. 21.

Liquor of Libavius, III. 181.

Lixiviation, 162.

Loadftone, III. 221.

Looking-glarH-% filvering of, III. 184.

Luc, M. de, 172.

Luna cornea, III. 348.

Lunar nitre, III, 340.

M
Magnefia, 371, II. 219.
Magnefian vitriol, II. 205. Nitre 210.

Marine fait, 214. Borax, 210.
Magnetifm, III. 217. Animal, 293, 294.
Malachite, III. 296.
Malleability, II, 402.
Manganefe, III. 22—32.
Maniac, IV. 95.
Manna, IV. 42.
Marble, II. 189.
Margraaf 's method of making phofphorus,

IV. 373.

F f 4 Marine

456 INDEX.

Marine fait, fee fait common,

Maftic, IV. 81.

Medicine, univerfal, 33.

Melaffes, IV. 31.

Mephitis, xxxviii. et feq.

Mercury, III. 94 — 156.

Mercurial water, III. 124.

Mercurius dulcis, III. 143.

Metals, lxxiii. II. 400. et feq.

Microcofmic fait, IV. 354.

Milk, IV. 300 — 315.

Millipedes, IV. 423.

Mindererus, fpirit of, IV. 204.

Mineralogy, 221.

Mineral pitch, III. 440.

Mineral waters, their contents, III. 443.
different claffes, 451 — 459. examina-
tion from their phyfical properties,
459. — by re-agents, 461. — by diftilla-
tion, 493. — by evaporation, 496. Com«
pofed artificially, 510.
Minium, III. 201.
Mifpickel, III. 224.
Molybdena, II. 263 — 269.
Monge, M. xxxi.
Mongez, M. 224.
Monnet, M. 214.
Morveau, M. lxxxii, 176.
Mucilage of flour, IV. 105.
Mountain green, III. 296.
Mucilaginous extracts, IV. 17.
Mucofe-extraftive fubftance of flefh, IV. 397.

Mufcles

index. 457

Mufcles of animals, IV. 394,
Mufk, IV. 411.
Myrrh, IV. 85.

N

Naptha, III. 440. et feq.

Naial mucus, IV. 339.

Natrum. See cretaceous foda.

Neuroptera, IV. 255.

Neutral falts, lxxii. II. 56.

Nickel, III. 11 — 22.

Nitre, II. 72 — 88. Rhomboidal, 88.
Ammoniacal, 134. Calcareous, 162 —
167. Magnefian, 210. Argillaceous,
246. Barytic, 258. Metallic. See
the feveral metals.

Nitrous acid. See acid nitrous.

Northaufen, fuming oil of vitriol of, III,
247.

Nut-oil, IV. 56.

Nutrition, IV. 268.

O

Oils, IV. 47.

Ointment, mercurial, IV. 323.

Olibanum, IV. 82.

Opacity of metals, II. 401.

Opium, IV. 19.

Ores, affaying of, II. 410. et feq. See

the refpective metals.
Ornithology, IV. 234.

Orpiment,

458 INDEX.

Orpiment, II. 436.

Oxyginous principle, xxxv. et fcq,

Pallas, Dr. difcovers native iron, III. 218*

Pafcal, 169.

Petroleum, III. 439 — 443.

Philofophical oil, IV. 49.

Phlogifton, 131, et feq. II. 350. See alfo

Combuftion and Calcination.
Phofphorus, IV. 369 — 382. 402.
Phofphoric acid. See Acid Phofphoric.
Pitch, IV. 79.
Pit-coal. See Coal.

Plants and animals contain iron, III. 218.
Plafter- ftone, or plafter of Paris. See Vitriol

of Lime.
Platina, III. 383 — 407.
Plumbago, II. 391 — 399.
Ponderous earth, 368.
Ponderous fpar, II. 250.
Pot-am, IV. 130. See Alkali Vegetable,
Potatoes, IV. 94.
Pott, 214.

Pottery, glazed by fait, II. 101.
Precipitate per fe, mercurial, III. in.
Precipitation, 71.
Prieft) : , Dr. xxxviii. 177.
Principles, 88. et feq.
Proof liquor, IV. 109.

Prouft,

jndex. 459

Prouft, his experiments on the refidue af-
ter the diftillation cf phofphorus, IV,
360.

Pruffian blue, III. 255.

Purple precipitate of Caflius, III. 370.

Putrid fermentation, IV. 217. Of vege-
tables, 220. Of animals, 433.

Pyrites, II. 357. III. 222. 303.

Pyrophorus, II. 241 — 244. IV. 204, 205.

Quadrupeds, IV. 224, et feq.

R

Rancidity corrected, IV. 320.
Rape, oil of, IV. 56.
Ray, John, 177.
Realgar, II. 436.
Rectification, 160.

Redu&ion, or revivification, 155. by phof-
phorus, IV. 381.
Rennet, IV. 302.
Refins, IV. 73 — 82.
Refpiration, 182. IV. 261.
Roafting, 154.
Rock cryftal, fufed, 217.
Root of vegetables, IV. 2.
Rofe-coloured precipitate of urine, IV. 352.
Rotrou's folvent, III. 65.

Saccharine

460 INDEX,

Saccharine matter. See Sugar.

Saffron of Mars, III. 236.

Sago, IV. 96.

Salep, or Salop, IV. 96.

Saline fubftances, 351 — 366. General Facts
refpecting them, II. 278 — 289. Their
properties confidered at length, 289 —
308. Their elective attractions, 308—

324-
Saliva, IV. 333.

Salino-terreftrial fubftances, 367, et feq.

Sal-ammoniac, II. 137 — 146. Sedative, 146,
Sparry, 147. Cretaceous, 148 — 153.

Salt of Seignette, IV. 186.

Salt of Sylvius, II. 90 — 94.

Salt, common or marine, II. 95. calcare-
ous, 167 — 172. argillaceous, 246, ba-
rytic, 258.

Salt, volatile of amber, III. 419.

Sandarack, gum, IV. 81.

Sap, IV. 8,

Scammony, IV. 83.

Scheele, xxxix, &c.

Schwediawen, Dr. his refearches concerning
ambergris, III. 436.

Secretion, IV. 261.

Sedative fait. See acid of borax.

Seeds, IV. 5.

Selenite. See vitriol of lime.

Seminal matter, IV. 340.

Senfibility,

INDEX, 461

Senfibility, IV. 275.

Serum, IV. 293.

Serpents, IV. 239.

Siderite, III. 226.

Siliceous earth. See earth.1

Silk-worms, IV. 324.

Silver, III. 326 — 355.

Soaps, metallic, IV. 54. Starkey's, 78. com-
mon, 320. acid, 322.

Soda. See alkali mineral.

Soluble tartar, IV. 185, et feq.

Sorrel, fait of, IV. 26.

Sparry tartar, II. 117. — foda, 118. fluor,
173. clay, 247.

Spar, ponderous, II. 250.

Spermaceti, IV. 413.

Spirit, ardent. See ardent fpirit.

Spirit of nitre. See acid nitrous.

Spirit of fait. See acid marine.

Spiritus reftor, IV. 66 — 73.

Starch, IV. 97. 103.

Steel, III. 230.

Stem of vegetables, IV. 3.

Stigmata, IV. 264.

Stomachs of animals, IV. 266,

Stones, 225.

Storax, IV. 76.

Strafburg turpentine, IV. 79.

Sublimate, corrofive, III. 131, et feq.
fweet, 143.

Sugar, IV. 31 — 43. of milk, 306.

Sugar cane, IV. 31.

Sulphur,

462 INDEX,

Sulphur, II. 354 — 391.
Sweat, IV. 338.
Synthefis, 5 — 7.

Tacamahaca, IV. 80.

Tartar, IV. 178.

Tartars prepare a fpirituous liquor from

milk, IV. 302.
Tears, IV. 340.
Tempering of fteel, III. 239.
Tentacula, IV. 257.
Teft for difcovering copper, III. 310.
Tetraptera, IV. 254.

Thouvenel, on the flefli of animals, IV. 395=
Tin, III. 156—188.
Tinned iron, III. 289. copper, 322.
Tolu, balfam of, IV. 75.
Tombac, III. 320.
Torricellius, 168.
Tragacanth, gum, IV. 44.
Trudaine, Mr. his lens, III. 359.
TfirnhaufTen, the effect of his lens on gold,

III. 359.
Tungften, II. 269 — 277.
Turbith mineral, III. 117.
Turquois ftone, III. 298.
Tutenag, III. 76.

U

Urine, IV. 342—353.

Varnifhes,

INDEX 463

Varnilhes, IV. 178.

Vapour of water, 195.

Vegetables, IV. 1, et feq.

Vegetable alkali. See cretaceous tartar.

Veins metallic, II. 408.

Venice turpentine, IV. 77.

Verdigris, IV. 209.

Vefl'els of tin, an inquiry into their whole-

fomenefs, III. 178 — 186 — containing

preparations, clofed by an amalgam of

tin, 180.
Veffels, 153. Of vegetables, IV. 6.
Vinegar, IV. 200. Concentrated by froft,

201. Radical, 211. Produced with

milk, 305.
Vipers, IV. 419.

Vitrification, 155. Of Gold, III. 360.
Vitriolated tartar, II. 60 — 67.
Vitriol of lime, II. 153 — 162.
Vitriol, oil of. See acid, vitriolic.
Volatile alkali. See alkali, volatile.
Volatility, 145, et feq.

W.

Wallerius, 214.

Water, its formation, decompofition, &c,
lxix. 184, et feq. II. 346, decom-
pofed by iron. III. 240. See mine-
ral waters.

Wax,

464 INDEX

Wax, produced from oils, IV. 49. Vege-
table, 5J. Of the ears, 339. Bees,
426.

Wedgwood, 152. 163.

Welding, a property common to platina as
well as iron* III. 403.

Whey, IV. 302.

White parts of vegetables, IV. 392.

White of eggs, of the fame nature as ferum,
IV. 415.

Wine, IV. 140.

Wolfram, II. 276, 277. III. 224.

Wood, IV. 3.

Wool, affords a large quantity of faccharine
acid, IV. 41. Takes the beft dye,
108.

Worms, IV. 256.

Woulfe, his apparatus for diftillation, IL

84.

Y

Yolk of Egg, IV. 416.

Z.

Zaffire, II. 455.
Zoology, IV. 226.
Zink, III. 67. — 94. 324.
Zwelfer's faffron of Mars, III. 282.

Table I.

The Divijion and Characters of the Eight Clajfes of Animals, hy Daubento;
ANIMALS.

Having an Head.

The moft Part
having no Head.

With Noftrils.

Without Noftrils.

With Ears.

Without Ears.

Two Ventricles in the Heart.

One Ventricle in the Heart.

The Heart varioufly formed,
or unknown.

Warm Blood.

Blood nearly cold.

A whitifh Fluid, inftead of
Blood.

Infpiring and expiring the Air frequently.

Infpiring and expiring the Air, \ Admitting the
at long Intervals. j Air by Gills.

Admitting 1 *J° aPPa,ent

the Air by Entrance or

Spiraculaf Aperture to

| admit Air.

Vivaparous.

Oviparous.

With Teats.

Without Teats.

i ft Order.

Quadrupeds.

2d Order.

Cretaceous
Animals.

3d Order.
Birds.

4th Order.

Oviparous
Quadrupeds.

5th Order.

Serpents.

6th Order.

Fishes.

7th Order. | 8th Order.
Insects. Worms, jj

Four Feet
and hairy Skin.

Fins and
no Hair.

Feathered.

Four Feet
and no Hair.

Scaly, without
Feet or Fins.

Scaly, with
Fns.

Having
Antennas.

Having nei-
ther Feet
nor Scales.

I

Table II.

Quadrupeds ', divided according to the Syflem of B r i s s o n.

Orders.

SECTIONS.

GENERA.

QUADRUPEDS,

Without teeth

5 Hairy (kin
| Scaly

With teeth.

With grinders only ■

Grinders and canine teeth only

Incifive teeth in the lower jaw only.

Ungulated feet

Ungulated feet,
and two incifive
teeth in each
jaw.

Four incifive teeth
in each jaw

Four incifive teeth
in the upper, and
fix in the lower jaw.

Six incifive teeth in
the upper, and four
in the lower jaw.

. 5 Hairy (kin •

( Bony covering or fhell ■

in.
riv. -

Incifive teeth in
both jaws.

covering or (hell
■ __^_ 3 Two long tufks and a trunk

t Two long tulks, no trunk

Ruminant, ungulated ; fix incifive teeth

r f Turned f Fore legs longer than hinder legs

f Ruminant, with \ S-imPle3 ^Pwards: * The leSs of e1ual lenSths

< cloven feet; eight <

£ incifive teeth. I Branche-d homs

L No horns < ■

The hoof entire. •

The Hoof cloven ■

Three ungulated toes on each foot, —

]. ., . -e „. . ... , { Two incifive teeth in each jaw,

J Four ungulated toes before, three behind, j Ten inciftve {eeth jn £ach Jjaw>

Four ungulated toes on each foot

Ant-eater Myrmecopbaga.

Manis Pholidoius.

Sloth ........ Tardigradus.

Armadillo Caiapbra£ius.

Elephant Elepbas.

rned back
rned fideways

Sea Cow . , .
Camel ....
Camclopardalis
Goat ....
Sheep ....

Ox

Stag

Mufk

. Odoiiiuis.
. Came! ;/s.
.Girajfa.
. Hircus.
.Aries. -
.11 ,.
. Ceruus.
. Tra^ulus.

f Spines on the body

XII. i

Without canine teeth <(

Without fpines.

. Tail flat and fcaly
Short tail {|| -

LonStail'{ Round
. Naked tail

With canine teeth

XIII.

Cxiv.

Six incifive teeth
in each jaw.

XV.

XVI.

J Without fpines on the body — - —

\ With fpines —

•J Separate toes —

\ Toes joined by a membrane foas to form wings -

• Horfe Equus.

Hog Sus.

• Rhinoceros . . . .Rhinoceros.

River Hog Hydros kterus.

Tapir Tapirus.

River Horfe .... Hippopotamus.

Porcupine Hyitnx.

Beaver Cajior.

-Hare Lepus

-Coney C unci, lus.

■ Squirrel Seiurus.

• Dormoufe Glis.

■ Rat ... .... Mus-

Shrew Moufe . . .Mufarancus.
Hedge Hog .... Erinaccus.

Monkey Sincia.

f Separate toes —

I The fore toe joined fo as to form wings

Six incifive teeth in
the upper, and eight
in the lower jaw.
Ten incifive teeth in
the upper, and eigl
I. in the lower jaw

( XVII.

hinT

ght C XVIII.

Five toes on each foot,

Four toes on the fore, and five on the hinder feet —

Five toes on the fore, and four on the hinder feet —

Firft toe remote from the other,
_ Firft toe near the other

Feet which reft on the heel in walking

Hooked claws which may be drawn back and concealed
j^The toes joined together by a membrane <

The toes feparate from
each other.

Pteropus.

Maucauco Profimia.

Bat ♦ . .Vejpctilio,

■ Seal Phoca.

Hyaena Byana.

Dog Cam's.

Weezel Mujiela.

Badger Meies.

Bear Urfus.

Cat Felts.

Otter Luira.

Mole

. Ttdpa.

■ Opoflum Philander.

• ♦

1'aUe 111.

The Ornithologic Syjlcm o/brisson.

orders.

I

I f

[Table IV. The Divijion of oviparous Quadrupeds, by Daubent<

O VIPARO US
QUADRUPEDS.

CLASS L The body covered with a (hell. } Confiding of iS fpecies.
, Tortoises. J

Genus I. Lizards ~)
which have the body |

fomewhat tubercu- (Confiding of 8 fpecie..
lated, and the tail \
flat. J

CLASS II. The body
naked, with a tail.

Lizards.

Genus II. Lizards
which have the tail
verticillated.

r Confiding of 12 fpecies

CLASS III. The body
naked, without 8 tail.

Genus III. Lizards "1
which have the tail I

round, fcaly, and > Confiding of 5 fpecies.
fhorter than the I
body. J

Genus IV. Lizards")

which have the tail I /-. r.n- , c •.-, r~a^;.

round, fcaly, and f Conflftl»S <* *7 fc™
longer thaa the body J

Genus V. Lizards ■%
which hive four I

fmooth. J

fer^i^^.

'Genus I. Toads O
the legs fhort. J

Genus II. Frogs "j
which have the body I Confiding of II fpecies.

long.

Genus III. Frogs "J

which have the toes [,-, <•«. c „ r • .

»„ • .i . >Conhihno; of o fpecies.

terminating in a f ° " r

„ broad flat furface. J

TT

Table V. The Divifion of Serpents by Daubenton,

Genus I. Rattle -fnakes •, or fuch as have a Rattle

Genus II. Serpents which have large fcales (Scuta)
beneath the body and tail ; without
a Rattle.

Boa, Linn.

SERPENTS. <

:ne-inaices ; or men as nave a j\.atue -»

at the extremity of the tail. j. It confifts of four fpecies.

Crotalus, Linnasi. J

i. It confifts of ten fpecies.

> It confifts of ninety-fix fpecie

y It confifts of thirteen fpecies.

i It confifts of two fpecies.

( It confifts of two fpecies.

Genus III. Serpents which have large fcales (Scuta)
beneath the body, and fmall fcales
(Squamae) beneath the tail.
Coluber, Linn.

Genus IV. Serpents which have fmall fcales beneath
the body and tail.
Anguis, Linn.

Genus V. Serpents which have the body divided
into annuli or rings.
Amphifbaena, Linn.

Genus VI. Serpents which have the flrin naked
fmooth.

Caecilia, Linn..

Table VI.

The Ichthyologic Syftem of Gouan,

FISHES
have either

The gills perfeft, -

Clafs I. ACASTHOPTIRTOII.

The fins fupported by fmall bones.

Order I. Apodes.
The ventral fins wanting.

Order II. Jugulares.
The belly-fins placed beneath the neck.

Order III. Thoracici.
The ventral fins placed beneath the bread.

Clafs II. Malacopterycii.
The fins foft, and without bones.

Order IV. Abdominales.
The ventral fins placed beneath the abdomen

Order I. Apodes.

Order II. Jufkilares.

Order III. Thoracici.

Order IV. Abdominales.

The gills imper-
feft.

Clafs III. Branchiosteci

Order I. Apodes.

Order II. Jugulares.

Order III. Thoracici.

Order IV Abdominales.

f I. rriMurut,

< 2. Sword-fifh Xiphias.

L 3- > Ophidism.

{i. Weveer -..-... Trachinus.
2 Vranofcopu,.

3. Dragonet CaUycnymus.
4- Blenny Bknnius.

ft. Goby Gobius.

" z. Cepola.

3. Dolphin Corypbxna.

4. Mackrel ------ Scomber.

5. Wrafi'c ------- Lalrus.

6. Gilthead ------ Sparus.

7. Cbtttadon,

, 8. — — — Sci'tiia.

^ 9. Perch Perca.

10. Father Lather - - - - SccprTna.

11. Surmullet ... - Mullus.

12. Gurnard ----- -Trigla.

j 1 3. Bullhead Cottiu.

I 14. Doree ------- Zeus.

I 15. Traciipterut.

L16. Stickle-back ... - - Gafterojleus.

n. Catfifh ----- . Silurtu.
\ 2. Mullet Mugil.

< 3. ■ Polynemus.
• I 4. . Tbeulys.

LS. Ebp,.

{I . Eel -------- Murana.
2. Gymnotus ------ Gymnotus.
3. Wolf-fifh Anarbicbtu.
4. ~— Stroir.a'cus.

5 . Launce ------- Ammodytes.

< 1. . - Lepadogajter.

I 2. Cod -------- Gadus.

f I . Flounder ------ Pleurcneilei.

\ 2. Sucking-fifh Echentii.

I 3. Upidopui.

r 1 . • Loricaria.

12. Atherine Athenna.

3. Salmon ------ Salmo.
4. Fiftularia.

I 5. Pike Ejox.

11 6. Argentine ------ Argentina.
7. Herring ------ Clupea.
t. Flying fifli Exotaelus.
9. Carp - •• Cyprinus.
10. Loche Cotitis.
I |, - A mi a.

^,2. - Mormyrus.

{I. Pipe-fifh Syngnathus.

2. Baliftes - - Baliftei.

, _ OJlracinn.

' . T.traodon,

5.' Sun-filh Diodon.

1 Angler L'phius.

I, Lump-fifh Cydopterus.

r j ______ Centrifcus,

1 _: /w«.

Table VII,

the Entomologk Method of Geoffroy.

Sections. ARTICLES.

ORDERS.

Seft. I.
Coleoptera,
Infefts with cru
taceous (hells over
their wings ,

£1

Either the fhell is hard, and
covers the whole abdomen,
and their feet have

Genera.

Platyctrus.

Ptilinus.

Scarabaus.

Copris.

Attelabus.

Dermejles.

Byrrhus.

Antbrenus

SECTIONS.

ARTICLES.

Genera.

in.

UV.

Ciftela.
Either five articulations to all the feet, fuch as the / c^uu

Elaur. '
Buprejliu
Bruchus.
Lampyris.
Cic ndcla.
Qmalyjus.
Hydrophylu,
Dyticus.
\. Gyrinus.

/ Melolontba.
I Pdonus.

Cerambix.

Lcptura.

Sunoco, US.

Luperus.

Crypt ocephalus.

Cricceris.

Altica.

Galeruca.

Cbry/omela.

Milabris.

Rhinomacer.

Curculio.

Boft, ichut.

Clerus.

Anthribus.

Scolylus.

C aft da.
V Ana/pis.

Ccccinella,

Tntoma.
' Diaperis.

Pyrochroa.

Can'haris.

Tenebrio.

Mordella

Notoxus.

Cerccoma,

Or, four articulations to all the feet, fuch as the /

Or, three articulations to all the feet, fuch as . . . j

Or, five articulations in the two firft pair of feet,
and four only in the hinder pair, fuch as . . . .

r1 ■■

II Or the /hell is hard, and covers! y.'

only part of the abdomen ;< y£
and their feet have I * *

('-

III. ... ; The (hell is foft, and their feet H'
have i III

j IV

Either five articulations to all the feet ....... Staphylinus.

Or four articulations to all the feet Necydalis.

Or three articulations to all the feet Forficula.

Or five articulations to the two firft pair of feet, \ j^e^(t

and four to the latter

I Mel

Blatta.

Either five articulations to the two firft pair of 7

feet, and four only to the latter j

Or two articulations to all the feet , Trips.

f Gryllus.

' ' ' I Acrydium.'

Or four articulations to all the feet Locujla.

Or five articulations to all rhe feet Mantes*

, . Or three articulations to all the feet

f Cicada.
Cmcx.
Aauccris.
Notont&a.

II Hemyptera, or infects whofe upper wings are half cruftaceous, half j Corixa.

membranaceous • S

Hipa.
PJylla.
Aphis.
Cberme.
. Coccus.

f Paptlio.
I Sphinx.
Infe&s with four farinaceous wings , •{ Pierophoius.

| Phalana.
L Tina a.

( I. . . . Three articulations to the feet . \
II. . . . Four articulations to the feet .

IV. . . . Infects with four naked mem- /
branaceous wings ..... *\

Vbcllula.
Perla.
Raphidia.
Ephemera.
Phryganea.
Hemerob.us.
Formica/to.
Puncrpa,
Crabro.
Urocerus.
III. . . . Five articulations to the feet «( Tentbredo.
Cynips
Diplolepis.
Eulophus.
Ichneumon.
Vefia.
Apis,
r ormica.

V> . . . Infects with two wings ............<

f Oeftrus.
Tabanus.
Afiks.

Stratiomys.
Mu/ca.
Stomoxys.
Volucella.
j Nemotelus.
Scatopp
Hyppobo/a.
Tipula.

Bibio.
L Culex.

Infects without wings

f Peiiculus.

P dura-

Forbicina.

Pulix

Chtli/er.

Amarus.

Phc.lar.gium.
■^ Aranea.

Men utlns.

Einculus.

Cancer.

Onifcus.

AJellus.

Stclcpendra.

lulus.

<

Table VIII. A methodical Divifion of Worms.

GENUS.

WORMS

ARE

Seclion I.
Naked worms

Scaion II.
Covered worms.

Order I. With univalve fhells.

Order II. "With bivalve fhells.

Gordius.

Lumbricus.

Afcarides.

Sanguifuga.

Limax.

Taenia.

1. Patella.

2. Haliotis.

3. Tubulus.

4. Nautilus.

5. Cochlea.

6. Nerites.

7. Trochus.

8. Cilindrus.

9. Voluta.

1 10. Strombis.

11. Buccinum.

12. Murex.

13. Purpura.

X uifutai

Porcellana.

15. Glob

1. Oftrea.

2. Chama.

3. Concha cordis.

4. Pettem

5. Mytulus.

6. Solen.

1. Pholas.

1 2. Balanus.

Order III. With polyvalvc fhelli. «j 3. Concha Anatifcra.

4. Chiton.

}'{

Seaion III.

Cruflaceous worms.

Order I. Naked polypi.

f I. Afterias.

I 2. Echinus.

r 1. Hydra.

1 2. Urtica Marina.

_ I Order II. Polypi, in corneous or r 1. Lithophyton.

ligneous cells. ' \ 2. Corallina.

Seaion IV. J TT „ ,

Polypi, } Order III. Polypi in cretaceous J 1. Corallium.

I 2. Madrepore.

cells.

Order IV. Polypi in foft and J r"
fpongy cells. £ *'

Efchara.

Spongia.

3. Alcyonium.

!

fn

X